I received an email from Cinda Jett at MapMuse.com. They’ve created an interactive map of art-supply stores throughout the U.S. I can’t vouch for its effectiveness, but pass it on because there are a lot of listings on it.
The idea is for artists to build upon what we have started by adding information about their local art supply stores to the MapMuse maps. The following information can be provided for each store- the name, descriptive text, a photo, contact information, and a link to a website. Through this kind of community effort, we hope to have the most comprehensive, and descriptive maps for artists to locate art supply stores at home and on their travels. There is an ADD and EDIT feature on the site (you can refer to http://find.mapmuse.com/re1/mmFAQ.htm#A4 if you have questions about making changes). Once a visitor suggests a change, it is reviewed for appropriateness and then posted within a few hours.
If you own or manage an art supply store, you may also want to consider a premium listing option for $10/ year. The premium listing has everything in the free listing, as well as an enhanced map presence, more photos, and a text link to your website below the map. Information about both of these options can be found on the Mapmuse.com site.