If you haven't checked out Google's Art Project, do it now. You can take a room by room, art work by art work, tour of the Van Gogh Museum, The Frick Collection, The Metropolitan Museum of Art, The National Gallery and many more.
The comprehensive virtual tour allows the visitor to take a virtual, self-guided, room-by-room walking tour of the whole museum. The visitor can navigate from room to room either by using a floor map or by following blue arrow links connecting the rooms. Camera icons indicate hotspots where the visitor can get a close-up on a particular object or exhibit panel.
The International Spy Museum in Washington, DC has a series of brain teasers up on their website to get you prepared to be a young James Bond. And they are a lot of fun!