Anybody got a real use for them? Are they the most pointless things ever invented, or what? Now I can see the point of the odd snap with the date on, or date/data imprinting for scientific purposes, but surely this is in general the second worst photographic gimmick of all time (the worst being so-called "panoramic" modes that simply mask part of the neg). I wouldn't include all such backs in this condemnation - others provide potentially useful facilities as well. But the question remains - WHY????