Here's a solution by DaRkL3AD3R in another thread... Have to add, though, you have limited control over Facebook and social connection apps....
Here's the info:
Actually turns out the "Running Services" page is NOT the same as running apps in the background. Services are unique, not the same as say, opening a game or web browser. Services are generally things you don't have to worry about and I recommend you don't shut down ANYTHING in this page.
Instead, here's what you want to do:
If 2.1:
Settings -> Applications -> Manage Applications -> Click 'Menu' Button -> Filter -> Running
If 2.2:
Settings -> Applications -> Manage Applications -> Click tab up top called Running
Everything in this list is an apk running in the background. Close apps you know you put on the phone (ie - Pandora, Dolphin Browser HD, AIM, Angry Birds etc) if you know you don't need it running anymore. Just be careful you don't close something you want, for instance Pandora when you are streaming audio.