GoogleMaps Mania did a very nice review of Codexmap yesterday. Gmaps mania is a great resource if you are interested in Google maps applications (but then if you are interested in that, you’ve probably already been to the site 8)).
He’s recently done a nice roundup of hardware-oriented product integrated with Google Maps, including the particularly interesting Pharos Trips & Pics Geologger.
Codexmap is live. An interactive books/maps experience. The basic idea is finding books on an interactive Google Map, based on the setting(s) of the book. You can find it here: http://www.codexmap.com. You can read more about it here: http://www.codexmap.com/help.htm.
Here’s a screenshot where I’ve navigated to the location “Sparta”.