You can now add a new title to Twitter’s resume: money saver. The programmers behind GasCalc have taken creative uses for Twitter to a new level and created a Web app that can help you track your gas usage — information that can help you save money in the long run. There’s no need to keep track of the information yourself or do any unnecessary calculations. After you’ve set up your account, just send a direct message to GasCalc with your miles driven, the price per gallon and the number of gallons entered, and GasCalc will do all the necessary calculating. You can do this either from the web app itself or via your mobile phone. Aside from simply calculating your gas usage statistics, the site can also predict what the price of a gallon of gasoline will be in six months based on the price of a barrel of oil, and it can calculate your gas usage and savings information to determine how much money you would save by buying a new car.