Did someone just help you?
Did someone take a lot of time to answer your question?
Did someone just do something totally cool?
Then click the [Helpful] link by their user information and give their rep a bump. If you said thanks for something, then click that link as a way of saying "thanks very much."
Mayhaps a rep bar instead of counter?
If you can find an SMF mod for that, I'll look into it.