Barefoot Running: How Humans Ran Comfortably and Safely Before the Invention of Shoes
http://www.sciencedaily.com/releases/20 ... 134241.htm <-- an introduction to the latest bare foot running report
http://www.barefootrunning.fas.harvard.edu/index.html <- full report funded by Harvard University and, in part, by Vibram USA®. Be aware!!!
I find the tips and FAQ are very useful. Though it is funded by a barefoot-type shoes manufacturer, the report is still very informative and objective on the topic.

