I was using the ipod feature while I was lifting at the gym with the included earbuds. Aparantly I disconnected the earbuds when I was done but never stopped the ipod or song. I noticed that the iphone made no external system noises, such as the clicks when opening or closing. Mind you, I did not know that the song was never stopped. I was upset, but could not pay too much attention to the phone as I was driving home. I tried to make a call but heard no sounds and the other party could not hear me. (i checked later) When I got home I performed an (iphone) reset and an itunes restore. No change. The phone would ring when called and the ring tone worked, but no sounds otherwise. No email notifications etc. I reset the iphone setings. No change. (other than my favorites were erased, my email signature was reset to the default from my iphone and a few other things.) When I was driving to work, still no change, i decided to try the earbuds to possibly make a call. As soon as I plugged in the earbuds, the ipod app opened and the cover art of the song in my gym playlist was up. The song was playing on the earbuds. I stopped the song, unplugged the earbuds and viola! All back to normal. I post just in case anyone has a similar experience.