Fuelly is one of the latest community sites appearing on the web.  Fuelly is a site that lets you track, share, and compare your gas mileage. Simply sign up, add a car or motorcycle, and begin tracking your mileage.

By recording and analyzing your mileage, you can see how much money you can save with small driving changes. You can also see how your mileage compares with EPA estimates and the mileage of other drivers using Fuelly.

Tips and a discussion forum also offer ways to save.