I have thought about getting backgrounder, but I figured it would demolish my battery life. I'm assuming you have it installed, if so, have you noticed a significant change in battery life?
If I would have thought of it, I would have included that in my must-have list, as well.
It is selectible. In other words, it doesn't just make every program run in the background. In an active program, you hold the Home button down for a few seconds, and you will get the message that it has been activated for running in the background.