I was having little issues like many others here. I came from an iPhone 3G and used the identical settings on my 3GS since I received it on Friday. However, I was getting MUCH worse life on the 3GS than on the 3G with the same settings and similar usage habits. Sooooo... I went to the Apple Store today and, sure enough, they agreed that I was seeing VERY bad results [they ran their special diagnostic on my phone]. I was already down to 42% when I got there at 3:30PM and the phone only had 3:30 hours of use and 8:50 of standby [not even a lot of calls!]. Now I am restoring from a backup to my new 3GS and hoping for better results.