Just opened my mail from the past week (who sends stuff in the mail anymore?) and had a brochure for new water quality trading market simulator partially produced by our very own--we'll call him occassional--contributor Rich Woodward. Unfortunately you have to be a student in a class for which the instructor has signed up to use the software, but the front material on the site is worth a quick look. Here's the link: http://edu.nutrientnet.org.