Hey if it works, get them rolling! :D

From one who rode, abeit breifly, on clay wheels back in the day, this looks like jumping from the Flintstones to the Jetsons.

It's not really a square wheel. It's basically a round wheel with wavy treads and sidewalls.

Cool i want one of those to my daughter down hill skateboard

Square, I don't think so. Gets your attention so I'll think of it as valid for marketing reasons. Interesting, hell yes I'm now in for two sets. For my uses they probably are no better than any normal skateboard wheel. If you apply a lot of side force on your wheels and better control would be welcome, I think it would be good for you to try a set. If you don't bother with intalling the metal spacers between the bearings in your wheels, I doubt these will be better for you than regular flat wheels. I view them as a stack of 3 inline wheels, the wave and depth of the tread may displace to the side some occasional small stones rather than go up over them.

Surely triple donuts would give all the benefits (less contact area and multiple materials) without the sine wave. I'm not sure what 'three lips for stopping' means when there is no braking mechanism. The so-called 'square' shape (when viewed from a certain angle) will make it a hit in a scene that thrives on uniqueness and innovation. Years ago a car tyre manufacturer invented twin tyres on each rim to aid water dispersion and allow greater width with the same contact area.

Seems like the wavy sidewalls would be more likely to catch on cracks and the such, but on the other hand might give you the control to launch. I don't know, but if you can make these as wide as you want the kids will go nuts for them, remember when you dreamed of tires, the WIDER the better. this is a cool idea, good luck with it.

I wonder if they will make some for rollerblades?

I do like them, but skeptical as I can't help being, I wonder if extra stability is just due to extra width... I suppose there are many ways of making wide wheels lighter... One is taking material off the sides with a fancy shape, but there are more.
Regarding the question to rollerblades, if they are In-line I have my doubts, as you change the angle when you turn, and the contact area would be uneven... causing vibrations. If they run flat I suppose they can be used for other stuff.
Anyway... again, nice idea that could work even if just for the looks of it!

All it is is a tread pattern on a wheel.
Watch the video and he says he discovered a way to take a set of curved shapes and make a "perfect square". But what he shows is NOT a square at all.
Then he takes that "shape" and applies it to a wheel and comers up with a conventional round wheel that has a tread with a sine wave pattern. Big whoop. He claims all sorts of things, including that it is faster than a regular wheel. I don't believe it.
If anything that sine wave is going to induce lateral vibrations in the wheel and to the skateboard or whatever it's mounted on.
And as for reduced surface contact, sure it may do that. But you don't need a fancy wavy tread pattern to do that. Just make a really narrow wheel. But what's the advantage? You'll have more pressure on the part that contacts the ground and therefore more wear on the wheel.