Coupon For A Free Bag of Riceworks

I've never heard of Riceworks before, but apparently they are gourmet brown rice crisps that are gluten-free. They actually look pretty good and there's a printable coupon for a free bag here:
http://www.freestufftimes.com/wp-content/uploads/2009/03/riiiiicejpg.pdf

You're supposed to be able to find these at Wal-Mart.