I received this link in an email a while back. It is titled Extreme Sheep Art and for good reason! The video explains it but here's a quick summary. This is a film of a bunch of guys from Wales who, frankly, have too much time on their hands, and a lot of sheep. They use their well trained border collies to move their sheep in the most amazing patterns you will ever see! The whistles you hear in the background are the sounds of dog whistles some shepherds use to tell the dogs what to do and how to move the sheep. I don't think there is anything more I can say to show the greatness of this video. Just take a look! It will blow you away!!