Perhaps a bit off topic, but I think that the best way to use miles is to earn them on the right card into the right program.

I made the mistake of earning lots of points with AMEX. At that time I thought that I'd be able to easily transfer them from AMEX MR for use with US Air (which was at that time my local airline).

Then, after 9/11, US Air dropped out and was replaced by United. However, transferring from AMEX to UA is not direct.

I finally got a Visa Mileage Plus card so that I can now earn my miles directly into the United program (and basically have stopped using my AMEX card).

FRANK