No matter how many times I read about the deep litter method I always find it interesting and fascinating. This is probably the best article on the subject I've read. It doesn't touch on using Diatomaceous Earth as I know some of you've mentioned you do. Supposedly it kills not only the bad bacteria and microbes but the good ones also. I'm sure all on this thread are familiar with Deep Litter Method (DLM) but here's the link anyway.
http://www.plamondon.com/faq_deep_litter.html