Well, my two inadvertant spins occurred during instructing, both during wingdrop stall lessons. The first was in a C152, easily recovered at the incipient stage. The second is the closest I think Ive come to becoming part of the landscape. It was in a Katana. The student applied ailreon at the stall and away she went. Having releived the student of control, I remember raising the flaps and commencing recovery from the spin (and letting out a series of expletives as well) at about 2,700 feet. The Katana spins very tightly, and recovery was finally completed at just over 1,400 feet. I was over water; if I had spun where I would normally have done the lesson, I would have had about 500 feet to spare. Food for thought.