Sorry to hear. It's a common problem. I upgraded to the HTC Incredible from the Motorola Droid and the battery was so bad, I switched back before the 30 days was up. It's is a very nice phone, but with such a small battery and such power, the battery life is not too good. It's a super fast phone, but overall, I felt like it wasn't much of an upgrade so I switched back.
Have you tried lowering the screen brightness? You did do the task killer, which should help. If all else fails, I think they are making an extended battery, but unfortunately that will make the phone more bulky. Go to Settings>About Phone>Battery Use and see what is using most of the battery. Turn off Wifi and Bluetooth. Turn off GPS - this is probably what is using a lot of your battery. Turn off the vibrate when you type. Reduce the amount of time the screen stays on before it turns off. Hope that helps.