Is it possible to get addicted to Yahoo Answers? I have seen people trying to win in forums as well! The number of posts, the best answers and so on! I mean get a life people!
Another such example was Orkut - a few years back, when people used to compete for the maximum number of scraps or fans or what not. Lately however, I believe that has stopped!
Edulix is another forum.

Welcome to the new addictions!! :) The safer ones on your health, but....