I got Advanced Task Killer. Has a blue icon. Blue gear surrounding a blue Droid phone. I think it was a buck in the market. Try it, and see if it helps. You have 24 hours to "return" it for a full refund if it doesn't help you out, but it helped my phone tremendously.
I was experiencing short lived battery life and app hangs before I switched over, and haven't had a problem since. You can even load it as a widget to auto kill all apps.
Let us all know how it worked for you.