Here is some interesting data that I was trying to find a while ago. A bunch of the links were broken. I fixed some of them and added a few more in 2006 (when the price leaped up again). I wonder if this will get us out of our SUVs and raise the CAFE standards. Probably not.
The big picture - gas price "temperature" map
National AAA
National flying J prices
National Pilot prices
National Love's prices
MSN gas prices site (needs zip code)
Yucca Valley, CA  
Kingman, AZ  
listing of regions, some states, and some cities from the DOE
gasprice.com home page
gaspricewatch.com home page