Electronic point-keeping system?

A physical "cash" system seems like one more set of small objects to try to keep track of. (WAY too many library cards in my wallet!!!)

I vaguely remember somebody posting a link to a really cool site designed for keeping track of this sort of thing. It was geared toward roommate issues, but if I remember correctly, it would be just perfect for something like this.

Unfortunately, I don't remember the name of the site.

Can anyone help me out, here?