It’s best to just NOT pay the fees in the first place. Get an Airline

This year the 2 airlines are integrating the Continental OnePass and United® Mileage Plus® programs but the credit card programs remain separate for the time being. It's like getting married but not trusting your spouse with your finances?
Your first checked bag is free every time you fly on Continental-operated flights when you purchase your tickets with your Continental Airlines Chase Credit Card (a savings of up to $50 per round trip). That's a good reason to use this Card. Earn miles every month + 100 bonus miles.
Use your Continental Airlines Credit or Debit Card to pay your monthly recurring phone and utility bills and earn miles — automatically — every month. Plus, earn 100 bonus miles when you register for this offer by April 30, 2011. Register with Promotion Code: TB3M28
At "Miles for Merchandise", you can use your OnePass miles and your Continental Airlines Credit Card to save up to 50% on everything from electronics and housewares to watches and fitness equipment on the Online catalog. The TravelBank card also gets you extra miles.
Elite members receive priority boarding privileges, priority baggage handling and many other special travel opportunities -- including complimentary upgrades for travel within the U.S. you also get Star Alliance Elite benefits
Or you could just fly SouthWest Airlines, where "bags fly free"