http://www.youtube.com/watch?v=Wzn8QhrYIvI Make sure you LISTEN to this video. Note the progress bar in Safari and how it moves in conjunction with the antennae being touched. I've been having a horrible time with my iPhone 4. The Apple store even replaced it this morning and the new phone has the same issue (thank you Apple store, you were 0 problems and I believe you're trying!). If you touch the phone on the bottom left (bridging the two antennae) while on a call or the internet, data stops instantly and calls are dropped. I placed the phone near some desktop speakers so that you could hear the interference typically heard when cell phones transmit data. When I touch the phone, you can actually hear AND see the data stop transmitting. I refreshed a website that I frequent and as it loaded you can see the progress bar pause and start as I touch and release the phone. This isn't a death grip of any kind. I and many others cradle the phone in their left hand while typing with the right - which is going to make this problem occur. In all fairness, I could not create this problem in Tampa this morning, but at various St. Petersburg, FL locations, it was 100% repeatable - leading me to believe some of the other information coming out that indicates it might have something to do with the towers that you are currently using. Either way, it seems clear that if you are near a "problem" tower or don't have the STRONGEST signal to begin with, the signal drops/shorts to a point where you can not make a call or receive 3G data when this spot is touched. So this is two different phones, same exact problem.