Friends of the Earth are running a competition to win £150 worth of books from their online bookshop. They have introduced a new feature where visitors can review the books, similar to Amazon's customer review system. Anyone who writes a review between now and the end of October will be entered into a prize draw.
There are more details on the FoE website. I notice they're selling Food for Free which some Bean Sprouts readers have recommended. I feel a book shopping spree coming on.