I was trying to use my iphone4 (ios5) today while travelling.
It looked like some app my daughter loaded onto her itouch pushed out to my iphone (some byproduct of a wireless sync setting gone awry).
I went to delete it, and poof - ALL my user installed apps were gone! A few empty folder remained, but the only apps loaded were like weather, notepad, itunes, etc.
I did a spotlight search, couldnt locate them either.
Had to resync when I got home- which...