Got too much spare time? Then you have to check this out:
The Official Line Rider
Line Rider was originally created by Boštjan Cadež, a Slovenian university student, in September of 2006. It almost immediately gathered a cult following and became the seventh quickest gaining keyword in Google. Since that time, the ‘toy’ has generated over 16 million views. Fans quickly noticed that they could create tracks, set them to music, and share them over YouTube.com. Currently, there are over 11,000 shared videos with many more to come.
Once you’ve had a play, you have to check-out some of the movies submitted by users : http://www.official-linerider.com/movies_page.html Some of these are absolutely amazing!