If you're racking up those frequent-flier miles, wouldn't it be nice to know that you're doing it with an airline that's giving you a good shake?
The people who publish the Consumer Reports Travel Letter think so. A reliable friend to bargain-minded travelers everywhere, the Consumer Reports Travel Letter (subscriptions:  999-7959) frequently ferrets out the best and worst in travel, and it recently turned its attention to the airlines' frequent-flier programs.
Which one is best for you? Well, it depends.
If you fly mostly short trips, it's best to hook up with a frequent-flier program that offers a high minimum mileage. Northwest, TWA, USAir, America West and Delta are good bets here, they say. (Delta offers a whopping 1,000-mile per-flight minimum, but it also requires you to collect a mess of miles.)
For fliers who fly farther, forget the per-flight minimums, and go with airlines that keep their credit requirements reasonable. For free trips within the Lower 48, Consumer Reports recommends just about anybody but Delta. For free trips overseas, they give the nod to Continental, TWA and Northwest.
Whichever program you choose, make sure you take advantage of each and every mile-earning opportunity it offers.