twiDAQ is a free online fantasy stock exchange game based on Twitter. You can buy & sell fantasy shares in any public Twitter account. The volume of followers, retweets, mentions and listings each account makes counts towards that stock's earnings... twiDAQ is free to play online today - just sign up using your Twitter account to start trading!
Contributor to Wired, PopSci, SciAm, Dwell. Coauthor of The Science of Battlestar Galactica and Environmental Monitoring With Arduino