http://www.billpoint.com/promotion/sellervisa.html

You could buy something from yourself on eBay and pay for it with a mileage-earning credit card. No credit card fees, but you still have to pay eBay a listing fee and then a percentage of the final bid price.

I haven't really made sure it works (it's too much trouble to actually do, IMHO) but it might be an option for some of you who need a few miles to top off an award.