And while not mapping, John Resig's Ukiyo-e [2] project is one of the coolest projects I've seen in the digital cultural heritage space in some time. He's been applying image recognition to these incredible Japanese woodblock prints from museums, galleries, dealers, universities and libraries all around the world. Because these things are prints, there could be hundreds of prints from the same block master all around the world, but because the expertise in the field is so divergent, the cataloging practices are really inconsistent. Different institutions might call artists by totally different names (or think a print is by totally different artists). So he built a search-by-image search engine of hundreds of thousands of Ukiyo-e that finds and reunifies prints totally independently of their metadata. Which is cool when you find 5-10 of the same print in places around the world. But it's cooler when it matches 2 prints with totally different artists and publishers and dates because at some point after the first print was made, someone bought the block master, cut out the face and replaced it with another, then did the same for the signature [3][4].
Actually, The Vectorizer owes a big debt of gratitude to John and his brother Mike. Mike Resig is a geographer and was the first to show us a process for how this kind of automated identification is possible.
[1]: http://www.mapbox.com/blog/user-friendly-guided-feature-extr... [2]: http://ukiyo-e.org [3]: http://ukiyo-e.org/image/met/DP134583 [4]: http://ukiyo-e.org/image/mfa/sc214530