Need to cut string but don't have anything sharp? You can break even a strong length of string with this trick.
As shown in the video above, you can break even a fairly strong piece of string by creating a loop in the centre of your palm, wrapping one end several times around your finger, and yanking hard on the other end. If you want a more detailed look at this trick, check out this video on MetaCafe.
Break String Without a Blade [Hackaday]