My iPhone 4 did that too. All I had was the apple logo on the screen for 4 hrs. 😱I was sick to my stomach.
I pressed and held the home button and plugged it in to my PC and iTunes restored it ... 😀
I'll NEVER mess with it again.. well never say never LOL 🙄
Wow... 4hrs... you were much more patient than me! I was running about the place and googling like crazy within about 30 seconds 😱 I have no problem with restoring now though, except the inordinate amount of time it takes to sync everything back on. If it wasn't for that, I'd be trying JB every five minutes 😀