I don't really read many SFF books, but I'm just finished reading,(well listening to as I like audiobooks) "Someone Comes to Town, Someone Leaves Town" by Cory Doctorow. It is one of the most bizarre books I have ever read, but I loved every minute of it. It is so weird that even the description doesn't really do it justice. You either take a chance on this book, or quickly run for the hills.

http://sfreviews.net/doctorow_someone_comes.html

This is the free pdf download if interested. Corey Doctorow makes his books available for free download.
http://www.gutenberg.org/ebooks/18224