Interesting...my wife joined AARP when she was 25 or so. They kept sending her direct mail to join, and eventually she did so for the hotel discounts. I guess it's just a political action committee...they'll take donors regardless of age.

I have never heard of a 20% off discount on flights. That's pretty huge...I'm surprised it hasn't gotten more play around Flyertalk. How restricted is it? There have to be some unusual strings attached, right?