Peeling a potato without a knife
This also works for tomatoes. I made a marinara sauce the other day and needed to quickly peel fourteen romas. I boiled seven at a time, never boiled for more than two minutes, then about two minutes in the ice water. I cored them first (just cut the little stem at the top out) and cut an X in the bottom so the skins would slip off easier.
This one is not quite done:

