The above video may not look all that clear or understandable (I feel like I'm watching a tiny bug walking along a vine or something), but in reality this is an incredibly interesting (and much tinier) video than one might assume. What you see above you is a picture of a Myosin molecule walking along an actin chain. It has been filmed by a group of Japanese scientists from Kanazawa University (in collaboration with a few others) using a technique called high-speed atomic force microscopy.
For those of you unfamiliar with molecular biology, myosin is a molecule that is pervasive in all multi-cellular organisms. It serves a wide range of functions, although my personal experience with it has been (as usual) in the nervous system.
(to make the following section a bit easier on those unfamiliar with brain anatomy, here's a short and informative video)
Within the brain, myosin is often used to transport materials from the cell body of neurons down the axon to their terminal. Basically, many neurons "package" neurotransmitters at their soma (the bulky center of a cell), but they need to get these materials to the end of their axons where they can be released into neuronal synapses. They accomplish this by attaching the materials to myosin, which then methodically crawls up actin fibers that extend throughout the axon. In this step-by-step fashion, cells are able to transport proteins, neurotransmitters, and other materials internally so that they can function properly.
It's a bit hard to believe that anything so tiny could act so similarly to the way we all move about the world, but the proof is in the protein, as they say!