today, when I opened up my iphone, update sign was up which was urbanspoon application. so I tapped to install. but it was just hanging, no process. and I forced to quit it. but mine was frozen. reset it, it only showed me apple logo for hours. nothing happened. obvious fact I found was that back of iphone got warmer and warmer as I could feel. then after few hours, I got back to home, connected with itunes. it was recognized, but taken a long time to sync. finally, everything seems to be fine. but in any case, I restore mine now for sort of cleaning up and restart. I hope that Apple will update soon.