Plus 3 Network to make my ride a charitable cause. You sign up with the site, choose a sponsor and cause and then track your rides with your GPS unit. The system will tally your miles and your sponsor will donate money in your name to your cause.
Its a great idea and the only snag I can see in it is that my GPS unit is old and does not work very well under tree cover. I hope there's a way around that as I can't see myself upgrading to a nicer GPS unit in the near future.
But check it out and see if you can get signed up and start converting your rides into charity rides.
Update: Testing out the Tweetmeme widget.