Track your gas costs online with Fuel Frog
The service is easy to use and has a clean and user friendly online interface. Where it really shines though, is that it allows you to enter the information from your cell phone via Twitter. No more bundles of receipts or rushing to the PC as soon as you get home to record your fuel info. Its so simple you can do it in real time while you are waiting for your pay at the pump transaction to complete.
I have just started using Fuel Frog so I haven't had a chance to check out the monthly reporting yet but I expect it will come in very handy. At the least it will solidify my decision to carpool and encourage me to try and find more carpool partners. I am also a little bit scared to see how much I spend per month on gas. My only wish is that Fuel Frog offered a way to track two cars on one account so we could keep our house under one login, but two accounts will do in the meantime.