If you install iOS 4 and jailbreak, 1) Do you lose features like visual voicemail and MMS? 2) Can you remove/uninstall the jailbreak after editing the plist file and keep multitasking and wallpapers? 3) Do apps look at your iphone model to see whether it is a 3GS and will it lock out multitasking? For example, skype hi-def audio works only on the 3GS so they may block out multitasking on the 3g even though it's unlocked with a jailbreak. 4) If you single click the home button while running an app, does it close the app or just keep it multitasking? 5) How well does the iphone 3g run with only 2 tasks multitasked, for example safari and skype. Thanks.