Finally got around to reading John Avlon's Wingnuts: How the Luncatic Fringe is Hijacking America. It is a little on the short side, but a very nice overview on the culture of partisanship and how the independent movement is ultimately a Libertarian movement.
I think quite a few people here will be checking out Nick Gillespie's Declaration of Independents sometime soon and I think Avlon's work would be a good book to throw in the bag with it.