So if you go into Settings --> Power you have the option of performance settings. From there you can pick High performance, Normal or Economy. When I tried using the Economy setting I had a dramatic improvement in battery life but my ee-mail did not seem to get pushed and certain notification settings seemed to get changed, although I was not keeping track of what they were because I did not realize why they had changed.
Does anyone know exactly what the 3 different settings do exactly (asside from keepng my phone from getting e-mail when asleep)?
Everything except performance mode turns something off. Usually it's something that you probably want running, such as background data. I don't know that even HTC documented the exact changes in each mode.