The best way I have found to earn flexible miles without flying is with my Sheraton Club International (SCI)/American Express Optima credit card. The card is free; the miles never expire (until you transfer them into certain frequent flyer programs like American but not Continental); and you can apply the miles to over ten different airlines/hotel partners. Joining SCI is free and you don't need to stay at Sheraton to have an active SCI account. Check it out (www.sheraton.com).