It has been posted here before, that the three smallest 35mm "full frame" cameras are the Minox 35's, Olympus XA's, and the Olympus Stylus (Mu) with the fixed 35mm lens. Since the Oly's use the sliding dust barrier and innovative lens designs, they are the same size open or closed. The Minox is a classic "clam shell" folder design (albeit in miniature and without the bellows), so it is much larger when it is opened for use.