Just a simple trick i made up i think. http://www.youtube.com/watch?v=RUhFO2L9Jlo
Nice one! Just as a tip for next time if you are using a light coloured string (which I’m sure 99% of us do), please try to wear dark clothing for videos. It just makes the string a lot easier to see. Also if you had been a bit closer to the camera this again would have made for easier viewing.
Nice trick though.