Old Video I Found on Differentials

In my quest for knowledge, I went to youtube and found this...was kinda interesting and gave a REALLY good explanation on how differentials work...thought it was kinda cool so I thought I'd share it, the beginning is slow so start it at 1:50...

[ame="http://www.youtube.com/watch?v=K4JhruinbWc"]YouTube- How Differential Gear works (BEST Tutorial)[/ame]