www.Fuelly.com

Fuelly.com 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. To date, 41,143 Fuelly users have tracked 1,084,297 fuel-ups in 55,439 vehicles over 305,756,822 miles of driving. There is even a mobile application that allows you to use your smart phone at the pump to update your account.