Scott of the Fuzzy Group is releasing his Radio documentation as an open source book, since O’Reilly used only a fraction of it in the Radio chapter of the upcoming Essential Blogging:
As the author of the O’Reilly Essential Blogging chapters on Radio, I clearly have a commercial interest in Radio. You’d think that I’d want people to just buy the Essential Blogging book and NOT give content about Radio for free. You’d think that but you’d be wrong. I really want to see Radio do well along with great people like Jake and Lawrence. And more documentation is pretty much always a frothy good thing for products.