Here’s a new OGL-licenced list of works in the UK government’s art collection, scraped for a Culture Hack Day -
http://kasabi.com/dataset/government-art-collection/
http://blog.kasabi.com/2011/09/22/hacking-on-culture-data/
The JISC OpenART Project is making good progress and considering which ODC licence to use. It should be both a great resource and a great case study -
https://dlibwiki.york.ac.uk/confluence/display/openart/Home
I’ve mentioned it before but this Seattle government list of public art with geolocation information is really good -
http://data.seattle.gov/dataset/Public-Art/7ckr-2zz9
And Freebase keep adding new information about visual art -
http://www.freebase.com/view/visual_art
Europeana are ensuring that all the metadata they provide is CC0 -
https://creativecommons.org/weblog/entry/29133
Their API isn’t publicly available yet, though! :-( -
http://www.europeana-libraries.eu/web/api/
Finally, for now, some of the National Gallery’s data now seems to be under an attempt at a BSD-style licence. The OGL would be even better… -