Despite the anguish being felt because of ultra high fuel prices, many airlines are still offering deep discounts on flights as the busy holiday travel season approaches. This is good news for consumers, but bad news for struggling carriers who absolutely cannot sustain this practice permanently. Consumers should take care how they book and pay for their flights and be careful which airlines they choose to fly with. Although no carrier appears to be ready to shut down altogether, consumers must remain informed in order to avoid being left stranded.The carriers most likely to find the going to be the toughest are the legacy carriers, which are defined as those carriers that have existed since before the current era of deregulation spawned competition in the early 1980s. Legacy carriers include: American, United, Delta, Continental, Northwest, and USAirways. There are many more discount carriers, but the major ones include: Southwest, JetBlue, Frontier, Spirit, AirTran, ATA, and America West. America West and USAirways recently merged, however.If you are planning a trip, always pay with a credit card to ensure that if your carrier does go belly up you aren’t left holding the bag. Credit card companies will refund your money if the airline goes bankrupt, but if you pay in cash you will have to get in line with all the other creditors. Good luck, in that case!Some of the best deals for the fall/winter period involve flights with discount carriers. The following list will give you a sample of just how good prices can be. Always check directly with the carrier for the latest prices as fare changes can occur overnight. Fares do not include taxes or security fees, refund policies vary, and restrictions apply.AirTran: Atlanta based AirTran is currently running numerous specials, particularly out of their home base in Atlanta. One way fares include: $249 to Las Vegas, San Francisco, and Los Angeles. Much lower fares can be had for flights originating from other bases by visiting their “Web Deals” section of their site for last minute bargains.ATA: Indianapolis based ATA recently instituted an across the board sale on flights starting as low as $44 from Midway to Sarasota. Other great deals include an $89 fare from Chicago to San Juan, PR and just $249 from New York to Honolulu.Spirit Airlines: Miramar, FL based Spirit Airlines has flights starting as low as $49 each way from Fort Lauderdale and Orlando to Nassau. The airline recently expanded its presence in the Caribbean so much of their current specials are geared toward encouraging travelers to go to this region. Visit Spirit’s “Syber Specials” section online for last minute deals too.Many of the legacy carriers do match the fares being touted by discount carriers. Currently, United, Delta, and Northwest are all in bankruptcy, while USAirways recently emerged from bankruptcy protection. Current labor problems at Northwest are also impacting the carrier, making flying with Northwest a truly “iffy” proposition.