That's great. Fun idea and good execution - well done.
Quick note (sorry to be the grouch): you're using OpenStreetMap map data, so you need to give OSM an on-screen credit. Not much to ask for the best source of map data in the world. :) Details: http://www.openstreetmap.org/copyright
That's a great data source. I'd previously tried this with freebase data, but it's nothing like comprehensive enough when it comes down to individual artworks.
I couldn't help but think of The Monuments Men movie that's coming out in February. If you wanted this to get some more publicity, I'm sure you could rebrand/position this in some way to ride that film's wave. Maybe something like "Be a Monument Man, and find art around the world!"
The parsed source is outdated and probably will be forever because it's crowd-sourced and can't keep up with changing exhibitions and lendings of paintings, which is a common thing.
The use case where I check my phone to find a painting or an artist near me also seems far fetched. A better scenario would be to have a map with museums near me and up-to-date information what they currently exhibit. You would need better sources for that.
On the technical side it's quite slow at the moment but the blown up thumbnails (where the Athenaeum also had thumbnails for fair use reasons but in a better quality) were not nice. I would keep them in their original ratio.
I assume that this was probably more an excercise to test-drive some new tech.
It sounds like you're actually not a fan of this implementation, not of the idea of a map of paintings. Would you still be opposed to it if the data was always accurate, the previews were larger, and the site was more responsive?
Valid points. There's a lot of hard work that would need to be done to make a really accurate data set. Sorry for the performance issues. The sites a little overwhelmed wih traffic right now.
Quick note (sorry to be the grouch): you're using OpenStreetMap map data, so you need to give OSM an on-screen credit. Not much to ask for the best source of map data in the world. :) Details: http://www.openstreetmap.org/copyright