Hello,

Maybe you're aware of the new big agreement of Google, Bing and Yahoo about microdata. They have officially launched shema.org to show how you should present the content of a site with rich snippets.

THE tool for rich snippets : http://www.google.com/webmasters/tools/richsnippets

It would be great to think about its implementation in order to be "good" for search bot. Galleries can use http://schema.org/Photograph or http://schema.org/Painting or other one...