Sterling posted this on Overunity.com a few days ago.

I talked with Spork33 today, after posting the above. He's the person featured in several of the DDFTTW videos.

He is convinced that existing laws of aerodynamics can explain this phenomena, and he is in process of composing a scientific paper for publication in a refereed journal that will detail the mechanics involved.

Bear in mind that you will not be able to just plop this on a flat surface such as a gym floor, give it a good push, and it take off accelerating. The device on the treadmill is analogous to a cart going along with a tail wind of the same speed, and the mechanism makes it go faster than the tail wind.
He said he has been assembling about 20 of these to ship out to a few people (primarily skeptics) from various forums who have asked to replicate the effect. He said that in doing several at once, the parts run around $40.00 USD. He asks another $5.00 for shipping. So at this juncture he's only doing it on a limited basis for scientific advancement. At that price, he's not willing to make very many.

Until the thing is mass produced, it will be fairly expensive. We (PES Network, Inc.) are in discussion with him about entering into an agreement to build and ship kits with adequate mark-up to make it worth our while, e.g. $80 retail. If you are interested (customer side or business side), please send an email to DDWFTTW.kit@pureenergysystems.com .

Because the gadget won't accelerate across a flat surface but will only move forward on a treadmill, the number of people wanting one will probably be fairly low, and the practical aspects perhaps lower yet.

It certainly is a scientific curiosity. Perhaps the principles underlying it may eventually spur some significant aerodynamic advancements in efficiency.