Procrastinators, listen up! Most cheap airfare for Thanksgiving travel was booked months in advance, but with just a few days until turkey day, you can still find a few relatively affordable tickets.

How is that possible? For one, demand is expected to tick down. The Air Transport Association of America (ATA), an industry trade association, foresees a 4% year-over-year decrease in the number of passengers traveling on U.S. airlines during the 2009 Thanksgiving holiday season. There are also the booking vagaries at work: Some carriers will slash prices on a seat still empty at the last minute, or will have lowered rates to a new destination.

But don t phone home with a promise you ll be there. Following a sharp decrease in business travel during the past year, most major airlines decreased flights and eliminated unprofitable routes, says Basili Alukos, an equity analyst at Morningstar who covers Southwest Airlines and the Legacy Carriers. Already this month, scheduled service departures from U.S. airports averaged 24,986 per day, down from 26,021 per day during November 2008, according to the ATA. As a result, flights during this Thanksgiving holiday travel period are likely to be near full. They re cutting capacity, or flights, faster than passenger volumes are dropping, says Alukos. That means airlines are less inclined to offer steep discounts.

The X-factor? Though most major airlines are on track to meet guidance for the fourth quarter, that could change depending on Thanksgiving travel. So, there s still a chance that in these last few days airlines will lower the price on their remaining seats rather than leave them unfilled.

Here are six tips to booking last-minute Thanksgiving travel on the cheap.

Scout out fare sales

Some airlines are still offering steep discounts for travel during the Thanksgiving break.

Southwest s Thanksgiving Deals are valid for tickets purchased by Nov. 23 for travel from Nov. 24 through Dec. 2. Also, AirTran is offering last-minute deals, many of which overlap with Thanksgiving.

Search every few hours

When looking for the cheapest airfare especially at the last minute it pays to search travel web sites every two to three hours. Fares go up and down constantly, day to day, hour to hour, and they can vary drastically, says George Hobica, the founder of AirfareWatchdog.com, which tracks cheap airfare.

Most major airlines employ fare analysts who check routes; if they see empty seats, they re inclined to slash the price on a few of those, he says. Consumers who keep checking fares will benefit since these reduced tickets go fast.

Check out markets with new airlines

One way to pinpoint cheaper destinations is by tracking areas with new service from airlines. This year, Southwest added several new markets, including Boston, Milwaukee, Minneapolis and New York s LaGuardia Airport. Meanwhile, AirTran Airways has been expanding its Milwaukee routes adding new stops. Also, this month Virgin America expanded to Florida with two daily nonstop flights between Fort Lauderdale and both Los Angeles and San Francisco.

Such increased competition at airports drives down airfare prices, Hobica says. For example, according to second-quarter 2009 statistics from the Department of Transportation, the average ticket out of Milwaukee is not only lower than 75 other U.S. airports, it's about $28 less than the nation s average fare.

Also, make sure to check these airlines if you re traveling to any of their new destinations. As of Friday, Virgin America s Fort Lauderdale flights still had seats left, including a one-way ticket from Fort Lauderdale, Fla., to Los Angeles on Thanksgiving Eve for as low as $99.

Look at business travel destinations

Most commercial destinations that rely heavily on corporate travelers experience a brief drought during Thanksgiving. In addition, the flights heading to these destinations take off despite plenty of unfilled seats; in an attempt to boost passenger volumes, airlines offer discounted prices.

Such routes often include travel between New York and Chicago as well as travel between Dallas and Denver, says Scott Berman, a principal at PricewaterhouseCoopers Hospitality & Leisure department. Flights between New York s LaGuardia and Chicago s O Hare airports start at $210 for round-trip tickets between Thursday, Nov. 26 and Tuesday, Dec. 1. That price rises to a minimum of $373 for flights between Nov. 29 and Dec. 4, according to Kayak.com.

Book travel for quieter days

In some cases, you ll find cheaper flights on Thanksgiving Day than the Tuesday or Wednesday preceding it.

For example, round-trip tickets from Chicago to Denver start at $275 for flights departing on Thanksgiving, compared with a minimum starting price of $335 on Thanksgiving Eve and $330 for the day before that, according to Kayak.com.

Of course, those who travel on Thanksgiving Day risk not making it to the dinner table if their flight is delayed or some other incident occurs. (Last Thursday, flights in the Eastern U.S. were delayed some for more than an hour by a Federal Aviation Administration computer problem.)

At this late hour, this is the best opportunity for better pricing both in a leisure destination or a commercial city, says Berman. In addition, he says, try to return on Saturday rather than Sunday, since that s when most people will be traveling back home. Or try to return the Tuesday after Thanksgiving weekend.

Search flights to Europe

While airlines began reducing domestic flights in the second quarter of 2008, most of them are just now starting to cut international flights, says Morningstar s Alukos. Currently, international flights still have more supply than demand, which leads to airfare discounts.

Travel from the U.S. to Europe is down in part because business travel to the continent is down, he says. That drop in business travel should be even more excessive during the Thanksgiving break. Most of the planes going to major commercial markets in Europe during the week are filled with business travelers, many of whom are home celebrating Thanksgiving and those seats are going east empty, says Berman.

Flights leaving New York for London on Thanksgiving start at $549 compared with flights that leave for London on Nov. 29, which start at $643, according to Kayak.com. Going forward, prices for U.S. flights to Europe will likely rise as airlines continue cutting capacity and major European carriers, like British Airways and Spain s Iberia, merge, says Alukos.