I've stopped using the HTC widgets (eg calendar, clock, friendstream) and selected GSM only and my battery life has improved greatly. I also leave the screen brightness set to auto.
My phone has been unplugged from the power for 8 hrs. My wifi has been on all day today, and I've made over 1hr 10mins of calls, used the browser several times, sent numerous texts and my battery life is still 68%.
Live wallpaper doesn't seem to make much difference.