I noticed a massive improvement in battery life after disabling widgets which like to poll the net for data: I've turned off the facebook widget and the foreca weather widget, and my battery hits two days pretty easily with light web, twitter, SMS and email usage, and a handful of short calls, and wifi enabled for a lot of that time. I haven't experimented properly to determine which is these widgets hits battery the most, though.

Of course, I can still run the battery dry within a few hours if I'm hitting it pretty hard. For that reason alone, I'd prefer a larger battery... but for now I've gotten rid of the requirement to charge every single night.