The most memorable prop from the TV show M*A*S*H would be the sign that shows how far away the character's hometowns were. But second to that is the still that Hawkeye, Trapper, and B.J. used to distill their own gin. The still was destroyed and rebuilt several times, and had several different looks, from a hillbilly moonshine-style tank to a mad scientist's lab. And where is it now?
Following the end of production on M*A*S*H in January of 1983, 20th Century-Fox donated the O.R. set and the Swamp set to the Smithsonian Institution in Washington, D.C. Included was the still. An exhibition was held at the National Museum of American History from July of 1983 to January of 1985. When the exhibition closed, the sets were packed up and placed in storage. The still is likely in a box somewhere in a warehouse.
You can read about the different stills and the M*A*S*H episodes that revolved around them, complete with pictures, at the show's biggest fan site, M*A*S*H4077TV.COM. Link -via Boing Boing