Here's my 6 day old 16GB 3GS w/ 3.1 OS.
3G ON (Full signal whenever I go)
WIFI ON (so it uses it automatically when I'm in range)
PUSH MobileME all ON
Push Notifications ON
Location Services ON
Brightness Default, Auto ON
Bluetooth OFF
After being on the phone for 5 minutes, my battery dropped 4%. Standby is pretty bad as well, I lose about 1% ever 20 minutes. I'm coming over from the Blackberry Tour (which has a monstrous battery life in comparison) so I'm quite spoiled. Regardless, it seems that a battery that only lasts < 1.5 days on standby is a bit weak. If this is the norm, please let me know.
Also, I realize some people suggest turning off push, location services, 3G, etc, but doesn't that greatly diminish the phones usefulness? When I'm out of the office, I'm constantly using the location services and push notifications. For me, it would reduce the phone's usefulness by about 50% if I don't have those features enabled.
That said, it appears the batter life of non 3.0 phones are supposed to be bettter. Is this an OS issue, or should I invest in a car and on-the-go charger?
Thanks!