I just joined a new local chess club. I remember from years ago a simple club rating system using index cards, but I can't remember the details. Does anyone know what I'm talking about or have a good intra-club rating system? 

The only thing I've ever done like that with index cards is keep track of a ladder tournament.

Use a ladder system.

Everyone writes their name on an index card, the weakest players at the front, the strongest at the back (or vise versa).  Now you put those all into a box, hopefully you can find individuals without much trouble =).

Ok, once you've made that box, here's what to do with it.  A player lower on the ladder can challenge somebody higher on the ladder (withen a limit.  in a 100 person ladder, you might only be able to challenge somebody say 10 rungs above).  Challenges cannot be declined.  If they win this challenge, you put the contender above that person on the ladder.  Alternatively, you can swap the locations of both index cards, both are valid systems.

New players start at the bottom of the ladder.

Thaanks.