I've written a review of the OpenStreetMap book by Frederik Ramm, Jochen Topf and Steve Chilton: http://oliverobrien.co.uk/2011/02/openstreetmap-using-and-enhancing-the-free-map-of-the-world/

I've also been using OpenStreetMap for some of my projects - for example it has provided the street network for this routed animation of the bike share scheme in London: http://oliverobrien.co.uk/2011/02/boris-bikes-flow-video-now-with-better-curves/