Want to know where to find the least expensive fuel near your home or place of work? Several Web sites now offer that information free, without the need to register. Sites we liked best show prices for regular, plus, premium, and diesel at local gas stations, and they tell you when the prices were last updated. They also link to maps to help locate the gas stations.

The first site derives its information from credit-card transactions at more than 85,000 outlets nationwide, plus reports from individual chains. Other sites mainly use reports from volunteer "spotters," which may or may not be verified by the Web sites. As such, they're good for general reference tools.

Here are four helpful sites:

• The Automobile Club of America directs you to the proper state AAA chapter based on zip code. Your chapter may have its own gas-price finder. If not, go to the California AAA site, which serves other states. It can show prices within a 3, 5, and 10-mile radius of an intersection you name.
  
  
• GasBuddy.com links to gas-price sites in Canada and the U.S. by specific state or province, county, or parish. Gas Buddy tracks only regular gasoline and diesel fuel. Some tested locations returned only regular gas price data, while others returned no information.
  
  
• Automotive.com highlights the lowest prices for each grade within your area when available. Prices per grade were spotty, at best, in our nationwide sampling.
  
  
• GasPriceWatch.com also spotlights the best local price, and it also lets you sort your results to find the most recently posted prices.

See the electronics blog entry Finding cheap gas on the Web for an evaluation of some of the Web sites listed above as well as other online gas price listings.