depressing day. charged full overnight. left at 645am. turned off bluetooth when I got to work at 715. wifi off, too. a few incoming gmails bleeped during the day and I got 1 phone call that lasted at most 2 minutes. NOTHING ELSE. left work at 5pm and the battery icon was yellow. what's up with that?
btw, phone is less than one week old. do I need some conditioning cycles?
I've got to read the info on batteries and get a back-up.
I find turning off auto-brightness and bringing brightness down to about 30% (which is still very bright) really improves battery life. That said, if your phone's off most of the day, this is unlikely the issue.
Something to look at is how much time your phone is "Awake" compared to its "Up time." If the numbers are close, something isn't right. For example, I once had an issue where it was syncing 24/7 with gmail or something, and sure enough killed my battery much faster than normal. I redid the settings and it solved the problem. See if in Accounts & Sync, any of the accounts constantly have the circular arrows. If so, try to resolve it by turning it off, manually syncing, and then turning it back on.
On the syncing note, don't let apps you hardly use auto-sync often. I don't really use Twitter often, so I turned off auto-sync. The few times I use it, I just refresh myself. Facebook I set to auto-sync once per day since I only check it a couple times per day, and just hit refresh if I need to.
Finally, in Settings-->Applications, you can check for running services. Also, the System Panel app will tell you what apps are running (beyond what Settings will tell you). Any apps I don't need that I see are always running, I uninstall.