You've probably heard of the 'Body Farm', maybe in one of Patricia Cornwell's books. It's the place where researchers place dead people, and expose them to the elements in order to study the process of human decomposition for forensic purposes. It's horribly gruesome, but undoubtedly provides loads of useful information.
Click on the title, if you'd like to donate your body to them. The site claims that they get 30-50 bodies donated each year. Which is kind of amazing, when you realize that you are responsible to pay for shipping the body to Knoxville, yourself. Although I'll be visiting Knoxville in the near future, I won't be visiting the Center. Sadly, it's not open to the public.