[youtube http://www.youtube.com/watch?v=IEVvEsEbl5I]
[youtube http://www.youtube.com/watch?v=14NY21zJcGo]
[youtube http://www.youtube.com/watch?v=HQ72jo7JcDk]
[youtube http://www.youtube.com/watch?v=7kdrsPRZnK8]
[youtube http://www.youtube.com/watch?v=uYWg3zSXiBw]
[youtube http://www.youtube.com/watch?v=pxkM3YTWu9s]
[youtube http://www.youtube.com/watch?v=ejweI0EQpX8]
[youtube http://www.youtube.com/watch?v=t3lSSp-3068]
[youtube http://www.youtube.com/watch?v=hXEjR1H3JKk]
[youtube http://www.youtube.com/watch?v=FHBSVhjufFo]
(via Mashable)
and my own one:
[youtube http://www.youtube.com/watch?v=w7td0agr7cg]