www.twincitiesgasprices.com is a weird little site where people go and post the price of gas they see. It's kind of interesting, but some people get really into it. But they've got a new feature called the Gas Buddy, seen here:
It's fun because it shows the highest and lowest reported gas prices in the twin cities metro. I put it in the sidebar so I can see how much I'm not paying for gas these days.