Need creative arduino project for art installation

I am building a large art car for burning man, I am planning on loading the interior with interactive art and lighting projects. If you have a cool arduino project, I am looking to put them in my art car during the event.
I might be able to fund a few projects, but if you would like to loan your project it would be great. If you have a way to do interesting lighting setups with many lights, that too would be good. Looking to automate a few things, if you are interested in more, follow my blog turjmahal.posterous.com