The first set looks like it was done with some rapid-prototyping type of machine. I imagine he has a piece of software that can crank these things out with ease.
At first I thought it was one of those laser cutters, like Xylocopa uses, but there's no telltale beveling or scorching on the edges of the pieces. Looking at one of the other videos he has, you can see minor ply scorching on the sides instead, which makes me think that these were made by hand with a scrollsaw.
Once upon a time, funny-shaped cog wheels where the bright future of advanced control logic. The concept was of course insta-killed by minicomputers.
Here are some from a Swedish university, which have been used in the intros of various technology-themed programmes on Swedish TV: http://www.youtube.com/watch?v=5zbSvdC-0Bc
I'm glad he wants to make a toy out of the intermittent drive gears at 2:00. Those are important for analog machines with step-wise anything, including multipliers. Someone has a hierarchy of machines starting with the five simple machines and including various compositions and modifications, but I can't find it. If I recall correctly, the intermittent drive branch enabled a more sub-categories than most branches. It's way too hard for biology to get things lined up well enough to do that.
A wristwatch with nice gears:
When we got our laser cutter at the Metalab, one of the first things that came out were these gears: http://www.thingiverse.com/thing:201.These are great to make on rapid computer-controlled manufacturing gear like a laser cutter or a CNC mill. They're easy to make, and they look just awesome.
Reminds me of a Reuleaux's drill:
Wow. I love the chaotic one around 2:15. It's kind of a shame this ends with "just" planetary gears.
I love the fish gear one. What other ways could you get that kind of periodic stop of rotation?
Seeing gears like that always brings back fond memories of a book I had in my youth, which I was thrilled to find freely viewable online. 507 Mechanical Movements
I'd love to see some of these fabricated out of steel or aluminum at a much larger scale and used to drive some ridiculous automaton.