GasPriceWatch.com
Apparently, this website posts "up to date" gas prices for any zip code. The information is gathered by people native to the area, and after submitting this information via the internet, it gets uploaded to their database which posts current gas prices for stations in their town or city, and indicates on what date the information was obtained.
The website makes this information freely available to the public. There is a verification process which slows things down a bit, but, even with a small number of watchers, this website could potentially help save folks some major $$$.
I'm willing to be a watcher for my neck of the woods even if it helps no one else besides me... but I have a feeling that this is information a lot of folks would be interested in...

- gator.