[Blink]

"Don't walk behind me; I may not lead. Don't walk in front of me; I may not follow. Just walk beside me and be my friend."

That's a Jewish quote (not joking)

I'm not really sure about your question. I don't really require people to do things for me before I do things for them (although I need to trust them), but I don't really actively go out to do things for others. However, I'll generally let @"CC.py" (or another good friend, but he's the best example) borrow anything if he needs.
I'm pretty passive in a lot of similar areas though, so I guess it makes sense?

EDIT: Found a counterpoint to the above -- I've bought pizza for @phyrrus9