I'm not sure if this works for all icons or just those on the shelf. If for example your phone icon disappears, the easy way to get it back without resetting or messing up your folders is to:
Hold any icon until it wiggles. Don't let go, just keep holding it for around 60 seconds. Then after around 60 seconds, let go and hit your home button to stop the wiggling. Your missing icon should then return to the shelf.
I've tried this a few times only on my JB'ed 3GS running 5.1.1
It works for me every time
Maybe you've installed Apple's iOS 6, the newest operating system for iPhones, iPad, and iPod touch, but do you know about all the tricks that are inside and how to use them?
Apple's latest mobile operating system, iOS 6, may have sparked a fury of Internet hate for the new Maps app, and I certainly won't wag my finger at anyone who misses Google's engine behind the Maps app, but plenty more goodies are tucked away in iOS 6 that you shouldn't miss.
This might be a silly question......but does anyone know how to turn of the notification for software update on the settings Icon. I have had this for almost since a little bit after an update was released... I just don't want to update my iphone4 to 6.0....................so anyway to get rid of it.