Gamification on Pinterest - Pinterest page listing all the gamification boards followed by ASTD, now the Association for Talent Development (ATD). We made the cut! Might take a while to wade through everyone's pins. Have fun!
Pointless (and Badgeless) Gamification - Good article on the disadvantages of leader boards. Unless you're in the top leader boards are often demoralizing.
Wamli.com one of the best gamification implementations I have seen.
TTLB Ecosystem - A now defunct, but very novel gamification of blogging using a custom social status ecosystem ranging from insignificant microbe to higher beings. Many bloggers were motivated to build market share and rise through the ecosystem by the opportunity to become an Adorable Rodent. We made it to Slithering Reptile. (Pin goes to TTLB Ecosystem page in the Internet Archive's Wayback Machine.)