Gasoline prices have jumped up 18 cents a gallon in the past week, the largest increase since the Energy Department started keeping records 15 years ago. What’s a driver to do, particularly out here in SUV-land? One suggestion is to fill up in Wyoming. Wyoming has the lowest gas prices in the country.

One reason gas is cheaper in Cheyenne is because Wyoming has one of the lowest state taxes on fuel. It’s 14 cents a gallon, compared to 22 cents in Colorado. Wyoming also produces a lot of oil and there’s a refinery in Cheyenne. And with two interstates converging in the city — I-25 and I-80, there’s a lot of competition for customers.

Another and more practical solution is to check the new gas websites cropping up:

A site called Gasbuddy.com, where volunteer spotters post the latest prices from gas stations around the country, has grown so fast that there are now 350,000 postings a week, triple the figure from a year ago. A similar site, gaspricewatch.com, plans to launch a service this month that will allow users to tap into its database from the road with a mobile phone. ….To keep its posted prices fresh, Gasbuddy.com offers its own version of a rewards program. Members earn points depending on how many prices they post and then can trade them for entries into drawings for free gasoline. Anyone can search for the cheapest rates on the sites by simply typing in a ZIP Code; on Gasbuddy, about 500,000 people a day are doing so.