First of all, congrats to all of you!! Without this forum I would never be able to get this far with my JB. 
I'm fairly new with JB. I got my IP4 at the end of Oct last year and I waited for iOS 4.2.1 before JB. Since I didn't want to have a tethered jailbreak, I had to wait for Greenpois0n to be released (last sunday). And here's my feedback for those newbies which, like me, are always nervous that something will go wrong.
JAILBREAK
Windows XP
Greenpois0n
iPhone 4, iOS 4.2.1
To start with, I don't care about unlock. I live in Europe and the carrier will release the iPhone if I ask them.
The JB went smoothly and worked fine on the first try. I strongly suggest you use the guide publised in http://www.iclarified.com/
Downloading Greenpois0n and performing the JB took a total of 5 minutes. And the phone has worked fine every since (plus no battery issues).
THEMES
The iOS 4.2.1 has "killed" a lot of the functionality in most themes. For example, if you install SlantedLock or AnalockHD, you can no longer set your own background image (no fault to the amazing developers, this is Apple's fault). So I decided to use a simple theme that would show the crisp wallpaper in the Retina Display: GLASKLART HD.

The HomeScreen also has a rotating wallpaper app, which I'll explain in a second.
For the LockScreen, I went with a stripdown version:

And the LockScreen has this charging battery (3D Gauge HDready):

FREE APPS
I've installed the following:
a 1derful HD WeatherIcon (theme) - adds a crisp icon to the Weather Icon
Activator - allows you to create "shortcuts" anywhere in the phone. For example, to turn my WIFI on/off, I just doubletap the statusbar.
Analock HD (theme) - an amazing theme for the LockScreen
AppInfo - you can check information regarding all apps, incluing size
BatteryInfo Lite - for information regarding the battery status (more accurate than most out there)
Black Status Bar_iOS4 (theme) - makes the icons in the status bar black
BytaFont - allows you to install dozens of different fonts. At this moment I'm using Celtic Garamond Font
CleanStatus - allows you to remove icons from the Status Bar.
Clear Status Bar (theme) - should be used with Transparent StatusBar, making the status bar in the LOCK and HOME screen invisible.
Cosca Signal Pack (theme) - theme the signal icon in the Status Bar
Cosca Wifi Pyramid (theme) - theme the wifi signal icon in the Status Bar
CyDelete - to directly delete Cydia apps from the HomeScreen (just like an Apple app)
Direct Closer - icons in the multitasking switcher will have a CLOSE pop by default
EnhancedTabs - adds a bunch of stuff to Safari, inclusing rules on opening a new tab and a button to close multiple pages
FakeCarrier - allows you to change the carrier name in the status bar to whatever you want
FakeClockUp - A MUST! Increases the animations, makes the iPhone look much faster (and it actually is faster). I would suggest you leave it with a maximum setting of 2X (it goes up to 10X!!)
Fast Copy - makes the copy/past menu that you have for texts pop-up much faster
file:// for MobileSafari - to edi local databases (such as the Analock HD theme)
Five Icon Dock - let's you have 5 icons in the dock bar (HomeScreen)
Five Icon Switcher - brings an additional icon to the iPhone multitasking switcher
Five-Column SB - have 5 columns of apps / folders in the HomeScreen
FolderCloser - auto-close folders when you launch an app
Glasklart HD (theme) - one of the best themes out there, just check my screenshots
i4 Invisible Slider (theme) - completely removes the slider from the LockScreen
iAnnounce - with incoming calls, starts with a sentence before the actual ringtone. For example, I have: Master, shall we spank "NAME"? followed immediately by the ringtone you have set-up.
iBlank - to create invisible icons in the HomeScreen, so you can "adjust" the layout of your apps / folders
Icon Renamer - you can rename any app icon (Apple included), just like a folder
iLlumine SBSettings (theme) - a nice looking theme for the SBSettings panel
iRetiner - to optimize all icons in the HomeScreen
iWipe Cache - clears the Sprinboard cache
LiveClock - the default Apple CLOCK icon is animated!
Lock Calendar - have your calendar visible in the LockScreen
Lockscreen Clock Hide - to remove the clock/date&time from the LockScreen
MultiIconMover - move multiple icons across the Springboard or inside folder (instead of doing it one by one)
MxTube - download videos from YouTube
No Bookmarks - stop Safari from automatically showing bookmarks if it starts with no page / empty page
No Icon Shadows iOS 4.2.1 (theme) - to remove the icon shadows, specific for 4.2.1
NoLockScreen - removes the LockScreen entirely, providing you don't use a password
PerPageHTML - an easier way to install widgets without using Winterboard and allows user defined wallpaper. Check also Facebook Widget for PerPageHTML and HTC Weather Animated PerPageHTML
Privacy - stop sending your phone's data to developers
Pull To Refresh Mail - you can refresh your mail inbox with a pull-down action
Pull To Refresh Safari - you can refresh a Safari page with a pull-down action
SBSettings - A MUST! It allows you to quickly toggle things like WIFI on/off, 3G on/off, etc. This is the main reason why my IP4 is JB. Installing this app will also install the following
Serious SBSettings HD (theme) - nice, cool icons for the SBSettings menu
StartDial - define where to go when you call the Phone app (favorites, contacts, dialer, etc.)
StayOpened - keep the AppStore open after you select a download or an update
SwitcherMod - lots of improvements for the app switcher
Transparent StatusBar (theme) - makes the status bar completely transparent. NOTE: there are two with this name in Cydia. The one that actually worked for me was created by styy1102
Time:Cal Widget (theme) - from LEXS1411, she does amazing things. This is NOT IN CYDIA, but it does look good.
Weather Icon - adds weather information in the HomeScreen to almost any weather app (like the default Apple, AccuWeather, Weather Channel, etc.) IMPORTANT - never put the icon on the DOCK!!
WiFi Passwords - display and copy passwords for all the wifi networks you added to the phone
WinterBoard - to manage the themes
PAID APPS
I seriously recommend the following paid apps (based on price/quality/utility)
biteSMS - this is all that the default SMS Apple app should be! Includes the possibility of replying to a SMS from ANYWHERE without exiting any application. You can also reply from the LockScreen and call the quickcompose from a locked iPhone.
Cyntact - adds pictures to the phoen contact list (just looks nicer)
FolderEnhancer - you can have folders within folders and unlimited apps per folder. I also love the transparent wallpaper option, which always displays the default wallpaper in the SpringBoard
Gridlock - place the icons wherever you want in the SpringBoard / folders.
iFile - it's like a Windows Explorer for your iPhone. Very useful if you want to install themes or widgets not available in Cydia.
Notifier+ - notification icons in the StatusBar and in the LockScreen for email, sms, calls, IM. Includes an independent reminder option for all off these.
PhotoAlbums+ - create pic folders directly in the iPhone, which can be password protected.
5-Row Keyboard iOS4 - I love this one! I can now have numbers as the first row in my iPhone keyboard!!!
I guess that's it.
If anyone needs any clarification, please let me know.
As of now, I'm JB for 4 days and it made my iPhone experience much, much, MUCH better. I have no battery issues, no freezes, no forced restarts. And I can still use all Apple apps, Apple Store, iTunes, backup the iPhone, download music, etc. If you are a n00b like me and mostly curious, just try the JB. Worst case scenario, just restore from iTunes (thus removing all JB software) and retrieve the backup.
Here's my current set-up:
View attachment 272436
View attachment 272437
I'm fairly new with JB. I got my IP4 at the end of Oct last year and I waited for iOS 4.2.1 before JB. Since I didn't want to have a tethered jailbreak, I had to wait for Greenpois0n to be released (last sunday). And here's my feedback for those newbies which, like me, are always nervous that something will go wrong.
JAILBREAK
Windows XP
Greenpois0n
iPhone 4, iOS 4.2.1
To start with, I don't care about unlock. I live in Europe and the carrier will release the iPhone if I ask them.
The JB went smoothly and worked fine on the first try. I strongly suggest you use the guide publised in http://www.iclarified.com/
Downloading Greenpois0n and performing the JB took a total of 5 minutes. And the phone has worked fine every since (plus no battery issues).
THEMES
The iOS 4.2.1 has "killed" a lot of the functionality in most themes. For example, if you install SlantedLock or AnalockHD, you can no longer set your own background image (no fault to the amazing developers, this is Apple's fault). So I decided to use a simple theme that would show the crisp wallpaper in the Retina Display: GLASKLART HD.

The HomeScreen also has a rotating wallpaper app, which I'll explain in a second.
For the LockScreen, I went with a stripdown version:

And the LockScreen has this charging battery (3D Gauge HDready):

FREE APPS
I've installed the following:
a 1derful HD WeatherIcon (theme) - adds a crisp icon to the Weather Icon
Activator - allows you to create "shortcuts" anywhere in the phone. For example, to turn my WIFI on/off, I just doubletap the statusbar.
Analock HD (theme) - an amazing theme for the LockScreen
AppInfo - you can check information regarding all apps, incluing size
BatteryInfo Lite - for information regarding the battery status (more accurate than most out there)
Black Status Bar_iOS4 (theme) - makes the icons in the status bar black
BytaFont - allows you to install dozens of different fonts. At this moment I'm using Celtic Garamond Font
CleanStatus - allows you to remove icons from the Status Bar.
Clear Status Bar (theme) - should be used with Transparent StatusBar, making the status bar in the LOCK and HOME screen invisible.
Cosca Signal Pack (theme) - theme the signal icon in the Status Bar
Cosca Wifi Pyramid (theme) - theme the wifi signal icon in the Status Bar
CyDelete - to directly delete Cydia apps from the HomeScreen (just like an Apple app)
Direct Closer - icons in the multitasking switcher will have a CLOSE pop by default
EnhancedTabs - adds a bunch of stuff to Safari, inclusing rules on opening a new tab and a button to close multiple pages
FakeCarrier - allows you to change the carrier name in the status bar to whatever you want
FakeClockUp - A MUST! Increases the animations, makes the iPhone look much faster (and it actually is faster). I would suggest you leave it with a maximum setting of 2X (it goes up to 10X!!)
Fast Copy - makes the copy/past menu that you have for texts pop-up much faster
file:// for MobileSafari - to edi local databases (such as the Analock HD theme)
Five Icon Dock - let's you have 5 icons in the dock bar (HomeScreen)
Five Icon Switcher - brings an additional icon to the iPhone multitasking switcher
Five-Column SB - have 5 columns of apps / folders in the HomeScreen
FolderCloser - auto-close folders when you launch an app
Glasklart HD (theme) - one of the best themes out there, just check my screenshots
i4 Invisible Slider (theme) - completely removes the slider from the LockScreen
iAnnounce - with incoming calls, starts with a sentence before the actual ringtone. For example, I have: Master, shall we spank "NAME"? followed immediately by the ringtone you have set-up.
iBlank - to create invisible icons in the HomeScreen, so you can "adjust" the layout of your apps / folders
Icon Renamer - you can rename any app icon (Apple included), just like a folder
iLlumine SBSettings (theme) - a nice looking theme for the SBSettings panel
iRetiner - to optimize all icons in the HomeScreen
iWipe Cache - clears the Sprinboard cache
LiveClock - the default Apple CLOCK icon is animated!
Lock Calendar - have your calendar visible in the LockScreen
Lockscreen Clock Hide - to remove the clock/date&time from the LockScreen
MultiIconMover - move multiple icons across the Springboard or inside folder (instead of doing it one by one)
MxTube - download videos from YouTube
No Bookmarks - stop Safari from automatically showing bookmarks if it starts with no page / empty page
No Icon Shadows iOS 4.2.1 (theme) - to remove the icon shadows, specific for 4.2.1
NoLockScreen - removes the LockScreen entirely, providing you don't use a password
PerPageHTML - an easier way to install widgets without using Winterboard and allows user defined wallpaper. Check also Facebook Widget for PerPageHTML and HTC Weather Animated PerPageHTML
Privacy - stop sending your phone's data to developers
Pull To Refresh Mail - you can refresh your mail inbox with a pull-down action
Pull To Refresh Safari - you can refresh a Safari page with a pull-down action
SBSettings - A MUST! It allows you to quickly toggle things like WIFI on/off, 3G on/off, etc. This is the main reason why my IP4 is JB. Installing this app will also install the following
Serious SBSettings HD (theme) - nice, cool icons for the SBSettings menu
StartDial - define where to go when you call the Phone app (favorites, contacts, dialer, etc.)
StayOpened - keep the AppStore open after you select a download or an update
SwitcherMod - lots of improvements for the app switcher
Transparent StatusBar (theme) - makes the status bar completely transparent. NOTE: there are two with this name in Cydia. The one that actually worked for me was created by styy1102
Time:Cal Widget (theme) - from LEXS1411, she does amazing things. This is NOT IN CYDIA, but it does look good.
Weather Icon - adds weather information in the HomeScreen to almost any weather app (like the default Apple, AccuWeather, Weather Channel, etc.) IMPORTANT - never put the icon on the DOCK!!
WiFi Passwords - display and copy passwords for all the wifi networks you added to the phone
WinterBoard - to manage the themes
PAID APPS
I seriously recommend the following paid apps (based on price/quality/utility)
biteSMS - this is all that the default SMS Apple app should be! Includes the possibility of replying to a SMS from ANYWHERE without exiting any application. You can also reply from the LockScreen and call the quickcompose from a locked iPhone.
Cyntact - adds pictures to the phoen contact list (just looks nicer)
FolderEnhancer - you can have folders within folders and unlimited apps per folder. I also love the transparent wallpaper option, which always displays the default wallpaper in the SpringBoard
Gridlock - place the icons wherever you want in the SpringBoard / folders.
iFile - it's like a Windows Explorer for your iPhone. Very useful if you want to install themes or widgets not available in Cydia.
Notifier+ - notification icons in the StatusBar and in the LockScreen for email, sms, calls, IM. Includes an independent reminder option for all off these.
PhotoAlbums+ - create pic folders directly in the iPhone, which can be password protected.
5-Row Keyboard iOS4 - I love this one! I can now have numbers as the first row in my iPhone keyboard!!!
I guess that's it.
As of now, I'm JB for 4 days and it made my iPhone experience much, much, MUCH better. I have no battery issues, no freezes, no forced restarts. And I can still use all Apple apps, Apple Store, iTunes, backup the iPhone, download music, etc. If you are a n00b like me and mostly curious, just try the JB. Worst case scenario, just restore from iTunes (thus removing all JB software) and retrieve the backup.
Here's my current set-up:
View attachment 272436
View attachment 272437
Last edited: