http://www.billshrink.com/ is a website that helps you get the best deal on gas, credit cards and wireless phone plans.
Here is a description from their website:
"BillShrink is a free cost-savings tool that works continuously to save you money on your everyday expenses. Given the vast number of complex offers and plans, such as those from the major mobile carriers and credit card issuers, chances are pretty good you’re paying more than you need to.
We make it simple to compare what you’ve got to what they’re offering. And if you’re like most people, that means significant savings. Isn’t that just how things on the Web should be? Incredibly useful, simple and free."