Tip to my non-flyertalk friends: check for airline partners. Many times we have to travel on an airline not of our own choosing because of price or schedule. Be sure to check if that airline is partner with our favorite airline. Many of my friends do not claim frequent flyer miles because they think they will never fly a particular airline again. In particular, they don't know that most foreign airlines have domestic airline partners.

In addition, because of the Continental --> Amtrak and Midwest --> Amtrak trick, you can essentially get $50 refund for every 5000 miles flown. Many airlines are partner with either Continental or Midwest. By transferring miles from these two airlines to Amtrak at 5000 miles increment, you can get $50 gift certificate per 5000 miles to many merchants.