I use the same program but with UA. One of the bonus programs with UA was spend $125.00/month from July, '06 thru Dec., '06 amd receive a 25000 mile bonus (which was paid in March, '07 IIRC). That's a pretty generous bonus IMO (with the milage earned on the $125.00 it came to a minimum of 32,500 miles which works out to about 43 miles/$!) This was offered as a celibration of the 25th anniversary of the Milage Plus program. They didn't do anything close to that this year though.

A co-worker of mine simply uses the Rewards Network rebate and receives between 10%-20% cash rebates and preferrs that to milage. That's another way to go, too.

It's my understanding that you can have multiple accounts with various airlines and play the game with whichever has the best bonus going. You just have to have seperate cards registered for each airline.