Just found that, searching on the net for a comprehensive quick-guide to mod_rewrite (again).
mod_rewrite is cool. I used it "often", as in it solves a good number of "beautiful url" problems.
But I say "often" with quotes, because I'm not using it often enough for the syntax to remain in my head.
This is a nice cheat sheet to pin on your wall at work :)
EDIT - Updated link