Things I've noticed on the battery:
#1 battery drain is display. Dropping the display to 25%ish brightness makes a massive difference in battery time while having a minimal impact on visuals unless you're in sunlight.
Live wallpaper battery usage in my experience has been minimal. What is more important than type of wallpaper is the color of it. Darker backgrounds in apps/home screens seem to use less battery than lighter ones. This is especially true when browsing the web on the phone. flipping through a lot of white-background pages burns through the battery a lot faster than dark ones in my experience.
Personally I only use the data when the phone isn't idle. So I set the phone to turn off data after 30 minutes when idle during the day and after 15 minutes when idle at night. I don't know if you can configure it this much in 2.1, but I am on Froyo.
constantly updating widgets burn through the battery because they keep using your data connection. This can be particularly bad if you are in a bad reception area as 1x connections suck up massive amounts of battery.
going into a bad reception area? turn on airplane mode.
Normally I pull my phone off the charger when I get up at 7am and put it on when I go to bed, which can be anywhere between 10pm and 2am. The lowest my battery normally gets is 40-50% by 2am, and my usage varies a LOT.
Biggest thing to remember is that like the man said, you can't use the thing constantly for 8 hours and expect it to last you 2 days on a single unextended battery. Tests have shown this phone has the best battery use on the market for droids.