I have been having this odd issue with my 3GS. If I am using any app, but most noticeably in mail or texting, when I hold my finger down on the screen, it jumps all over the place. This makes for an extremely difficult time when I am trying to send a text to someone. I've restored the phone twice, and done multiple hard resets, but the issue still is there. What makes things even more odd is the fact that sometimes the screen is fine, no jumping around or anything. The screen thinks that I am moving my finger rapidly up and down over a very small area. I guess it could be an issue with the digitizer. The phone is still under warranty, so I could just bring it in for a swap. I am wondering if anyone else has experienced this issue, and whether or not they were able to fix it on their own. Thanks in advance!