Comes up now and again, and has been given some serious thought, including stickers, a registra etc, but each time, not many folks have been keen.
Sometimes the best solution is to keep a piece of paper with the serial number on it in your drawer.
Even considered a "Reward if found sticker" for boards, until realising that stickers easily fall of boards,. Writing your phone number on the board with a permanent marker is low tech, immediate, and won't peel off.
From working in a pawnbrokers as a young lad, we found that serial numbers were quickly removed, defaced or replaced on stolen goods.
Always open to a fresh ideas, however.
