3GS battery life?

When I replaced my original (non 3G) 16GB iPhone with a new 32gb black 3GS, I was amazed at what a battery vampire the new 3GS phone was. I can be down in the 40% battery range at the end of a single day after starting at 100% in the morning. The old iPhone could go three days without a re-charge. I'm not doing anything different, in fact I use the phone less now (sign of the economy) than I used to.

Anybody else seen this?

FWIW, I also just picked up a second 3GS (this one a white 16gb model) for my other business, and it doesn't seem to be using up the battery as quickly.

Mitch Ives
Insight Productions Corp.
mitch@insightproductions.com