Be sure to check out this year's GSummit at http://GSummit.com
Stack Overflow and Stack Exchange: Programming the Programmers by Jeff Attwood, Chief Technology Officer of Stack Exchange Inc
We didn't set out to make participation a game in 2008, but when we considered what we wanted users to do that was constructive not just for themselves, but for the greater community, the game mechanics that programmers know and love came immediately to mind.
