[mir]

What an amazing video:
http://www.studiodaily.com/main/technique/tprojects/6850.html

Enjoy!

Could someone explain what that big blue thing walking on two legs is?

[Yggdrasil]

My computer isn't really cooperating, so I can't see the video, but I'd assume its a motor protein (like dynein or kinesin) moving around cargo (lipids).  From the article:

For instance, in the animation there’s a motor protein that’s sort of walking along a line, carrying this round sphere of lipids.

Biophysicists (e.g. Paul Selvin at UIUC) somewhat recently showed that motor proteins like dynein and kinesin do move with a foot-over-foot stepping motion using some really cool high-resolution fluorescence microscopy methods.