I've just run across an interesting site created by Strzelewicz Alexandre called Emacs Vs or Emacs Vote System. Users post their favorite Emacs tricks and the other users vote them up or down—much like Hacker News or reddit. The current favorite is yasnippet, a template system for Emacs.
This site is worth adding to your RSS feed just to keep up with the new submissions. If, like me, you're always on the look out for new Emacs tricks, this could be a good place to find them.