HTC Eris droid

I love my Eris! I love the Google op system. I love the touch screen. I love most of the apps. The one thing that I HATE about the phone is the quick dying battery! With the Google op system everything runs in the background eating away at your battery life. I downloaded advanced taskiller and task panel and both work well but I want my phone to last the whole day while I use it. Is that too much to ask for? Is there a way that I can use my phone and still keep the battery life good? I guess I will have to search and keep everyone posted.