I would encourage a Themed Costume Party, inviting everyone to dress up like one of their favorite masterpieces of art. It could be quite a lot of fun.
Editor's Note: I love the idea of creating costumes based on historical paintings or sculptures. This would be a good event for a school or youth group, but just as fun for adults. I hope you share your costume ideas in the feedback below.
Here is a Wikipedia entry about this masterpiece by Dutch painter, Johannes Vermeer.