We saw this article around an year ago and it inspired us to build Rootein http://rootein.com/ It's a web app, a Facebook app, has a mobile optimized version, features reminders and Twitter alerts as well. </ShamelessPlug>
Thanks for the mention Vijay. Just to add, Rootein also sends out reminders via email/Twitter DMs when it finds you slacking :) We have recently launched a Facebook app (http://apps.facebook.com/rootein) for Rootein. You can track your habits/routines from within Facebook. We just won't give you any excuses to slack :)