While the digital collection of the New York Historical Society is rather rigid and seems to be permanently incomplete (a good percentage of the objects do not have an associated image), there is a "special project" about the American Revolution that enhances the interactivity and learning opportunities of the user. You can send secret messages, create your own collections, ask questions to a historian, or pick a game or an activity for your class. Check it out at:
http://www.amrevonline.org/museum/