A couple of weeks ago it was reported that the iPhone 3Gs units were overheating. Some were so hot to touch that they burned. Some iPhone's screens started to discolor.
I had started to notice that my own iPhone which is still a 3G until my 3Gs finally shows up (I've been waiting 3 weeks!) got a lot warmer after I upgraded to iPhone 3.0. The issue seems to occur mostly when the phone is actually in use. I noticed it today while on a call, and I have noticed it while charging. Rumor has it that Apple's advice includes not leaving your phone in a hot car, limiting GPS app use, and other apps that cause the phone to stay on for long periods. Advice also includes not exposing it to direct Sunlight for too long. Umm... okey dokey then. I have noticed it just with normal use though.
Today on Twitter someone asked if anyone else was having a problem with their 3G overheating and I quickly replied. A Google search shows that others are having the issue as well. Anyone else notice an issue with their 3G overheating after the upgrade?
I hope that they fix this in the upcoming 3.1 update.