I am constantly looking for ways to increase the amount of FF miles I can earn. Latest find is from American Express. They are offering double AmEx mileage points for groceries and gas purches with your registered AmEx card through March 2010.
Others LL members have posted information about online shopping malls offered by airline FF programs. American Express has also gotten into the act. You can earn 3 points for each dollar spent at their online shopping mall: https://www.bonuspointsmall.com/directory.htm
Thanks for posting creative ways to increase your miles withouth actually flying. I too am constantly on the lookout for extra miles, and especially not to lose any miles. I have used the AMEX mileage points offered for gas and groceries when I am in the US. However, unfortunately, this does not apply when you use the card abroad for the same items. I will make a point of using their online shopping malls when I order things on line. Thanks for posting the link.