Do certain apps slow down the phone?

[macordiefool]

What would be the likely culprit of a slow to respond phone?
Is it the type of app you have running or can an installed but not running app slow you down?
Obviously if your memory is full you will have some issues but if it is not even half full, then are there certain ones that are bad for this?

I am mostly questioning the third party apps that require a jailbreak.

 

[Rob Mclovin]

The big one is Winterboard!

 

[macordiefool]

just having it on the phone or using themes and wallpaper and fonts etc?

 

[Applejuiced]

Just having it installed will do it.
With the 3G models is more noticeable than the 3GS since is has more system resources than the previous models.

 

[darngooddesign]

Its irrelevant on a 3GS.