Art Safari from the Museum of Modern Art
The Art Zone from the National Gallery of Art (requires plug-ins)
The Artist's Toolkit
Art Games from the Albright-Knox gallery.
Meet Me at Midnight Fun interactive art site from the Smithsonian American Art Museum.
Draw Online with Sketchfu
Blabberize Make photos or drawings talk! (Microphone required)
Wordle Customize artistic word clouds
Voki Create your own speaking avatar
Artopia allows you to explore all types of art and even create your own portfolio (for Upper Elementary and Middle School Students)
Art Detective Solve the Art Mystery!