"I thought, 'If I have this problem, others do too,'" said Metcalf, an independent technology consultant who founded and sold one of the Twin Cities' first Web site development firms back in the 1990s. "Why should this be so slow and so difficult?"

So after studying airline pricing, developing a system and fine-tuning it to be as user-friendly as he could make it, last February Metcalf unveiled Flyspy, an airfare search engine that graphically depicts the cheapest days on which to travel and the cheapest airports near a desired destination for the next 30 days.

On Flyspy, the chart for three-day roundtrip fares between the Twin Cities and Las Vegas, for instance, shows that a Thursday departure generally has the highest fare, so planning for a Wednesday, or better yet, a Monday or Tuesday departure, can save money.

For cities where there's a choice of airports, such as Chicago or New York, the chart will show the cheapest fare for each airport on each day. When you click on a day, the site shows a list of the scheduled flights, departure times and prices; if you choose a flight and click it, you're sent to the airline's site to book a ticket.

"Somebody who uses this site is really going to become educated ... and understand some things about airfare pricing," he said. Seeing how fares change by the day of the week you fly, "and understanding how the departure date relative to today's date affects the fare are the two things that jump off the page."

However, Nantell said, "the problem is that it's kind of complicated. ... If you're trying to educate people and there's all these options, the trade off between maximizing information and maximizing simplicity is a crucial one. Whether (Flyspy) has found the magic tipping point is not clear."

At this point Flyspy still is being developed, and it shows only Northwest Airlines fares for trips between the Twin Cities and 42 U.S. and four international cities. Metcalf said he expects to add airlines to the site soon, and that he plans to have fare data for all U.S. cities by the end of the year. He hopes eventually to add hotel and rental car price data.

While it makes sense to inform consumers about good and bad times to fly, "I'm not so sure consumers aren't already aware of that," said George Wozniak, president of Minneapolis-based Hobbitt Travel. "Most already know that midweek is the best time."