Not in the lost category so much as the inadvertantly-taken category: We once saw a guy paddling a canoe with a stick.  He stopped and asked if we had seen another party pass (we had).  Turns out, they had loaded and taken his paddle at a portage they were both crossing.  This guy was not in the best of moods; would have liked to have heard the conversation, when he finally caught up with that other group (we had no spare paddles on that trip, or would have given him one).