Austin Biofuels uses cotton seed or soybean oils for biodiesel. They have several retail customers.
There are over 20 Shell "Signature" stations selling B20 in the greater Austin, Tx area. There are a few other local stations selling B50, B80, and B99.

More information at Welcome to Austin BioFuels.com! including addresses of all locations near Austin with Austin Biofuels products, product details, test results, etc.