Urbis Morpheos by Stephen Palmer
Well, this has to be the most unusual book I've read in the last couple of years. For context, I've read 113 books since April 2009 (when I started buying on Kindle, so this is the total Amazon gives me). I probably haven't read more than 5 non-SciFi books (and 1 non-Kindle book) in that time; so I've read a reasonable amount of SciFi, mostly from the authors you'd see as mainstream - Neal Stephenson, Richard Morgan, Charles Stross, Peter Hamilton, Ian Banks, Robert Charles Wilson, etc.
Stephen Palmer is at a Whole Nutha' Level.