There is a great website call gasbuddy.com.
It basically uses members that have signed up to track gas prices. You can sign up and post gas prices as you see them throughout the day. You can even earn points and trade those in for chances to win prizes.
I haven't actually become a member, but I do use it to find out gas prices. I found that if I get gas near my workplace, I end up saving almost 20 cents a gallon compared to near my house.
It is another easy way to save a few bucks each time you fill up your tank.
If you use the gas stations that take cash or debit only, you tend to save quite a bit on gas.
I know...you are all whining "But they charge a 45 cent fee". This is true, but look at this for a moment:
If you put 15 gallons in your tank. It just takes a savings of 3 cents per gallon to cover that 45 cent fee. I am finding that I save at least 13 cents by going to Arco over the other credit card accepting stations.
I will admit that it is hard for me, because I am a rewards card addict. I love every mile I can get. Unfortunately I decided that the the 15 cents(1 mile = 1 cent in airline ticket value) is not worth missing out on a few dollars of savings.