As we're boarding a plane, a guy went to take his seat and someone else was seating there. They figured out that one of them was in the wrong airplane!
5 minutes later, one of the flight attendants announced: "this flight is going to Baltimore, if you're John X, please step to the front as you're going to Orlando, and if you're Paul Y, please exit this plane as you're going to Philadelphia." (then she apologized saying there's a glitch in the boarding pass scanning system, no kidding). (I almost got into the plane to Orlando, btw - it was all quite confusing).