Another neat kind of museum though, is the open-air, living museum. A great one in Ohio during the summer is Robin's Crossing in Nelsonville. It is peopled by students learning how to work at this kind of museum and volunteers.
A wonderful book I just found at the library is about the people who work at the Metropolitan Museum of Art in New York and is called simply "Museum" by Danny Danziger. Makes me want to work at a museum, right now!
The girls and I have made our own museum in the past. We started doing this when my oldest read about the boxcar children putting up their own museum. (second in the series by Gertrude C. Warner--"Surprise Island") We collected bird egg shells, feathers, rocks, shells, leaves, etc., made labels for each and then last year we put together our own art museum and a catalog. Tons of fun!