Stockbrokers sometimes offer large chunks of frequent-flyer miles to attract new clients. Just open a brokerage account and you qualify!
One large brokerage firm that recently offered this benefit is Fidelity. The brokerage aspect is different from the mutual funds, so discuss the frequent-flyer mileage bonuses with the telephone representative before committing. Your goal is how to fly free with miles, as well as how to make a ton of money in the stock market.