Okay, so this is an interesting confluence of my favorite hobby and my work.
Lots of misinformation here. This being perhaps the most important:
Originally Posted by SkiMangoJazz
eventually invalidating his patent by proving that he had sold his own skis during a time that on a technicality introduced during the litigation, he shouldn't have been
It wasn't a technicality. It was a requirement of the Patent Act. No inventor can get a patent if "the invention was ... in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States." 35 U.S.C. § 102(b). This isn't a "technicality"; it's what we lawyers call "black letter law" -- an absolutely unassailable statement that is taken for granted by practitioners.
Nelson put the product on sale more than a year before he filed an application disclosing the claimed invention. His lawyers tried to get around the problem by claiming that his offers for sale were experimental. The experimental use exception is usually argued against a "public use" more than a year before the patent application, and even in those cases, it rarely if ever succeeds. To the best of my recollection, no court has ever held that it can insulate against an invalidating sale. (Which, when you think about it, makes sense -- it's an experimental use exception, not an experimental sale exception.)
Unfortunately, I can't post the court's opinion here, because the attachment button won't work for me. Suffice it to say that it's about as clear as they get. And it wasn't even the only grounds on which invalidity could have been found: the court didn't reach K2's argument that RD's Fat Dog also predated the patent, because the patent was already dead based on Nelson's own sales. And of course, K2 went after him for their fees. That's what almost every patent defendant does.
Of course, all that is the patent litigator in me speaking. You can be forgiven for not knowing that.
But c'mon, people -- a little critical reading. According to Nelson's page, his "Dragonsword had the dimensions of the later highly acclaimed ski the K2 Public Enemy and then the K2 Fugitive, the K2 Shuksan, the K2 Piste Pipe, the K2 Axis XP, the K2 Apache Recon, and finally the K2 Instinct." Sure, some of those skis (the PE and Piste Pipe, for instance) have the same dimensions. But claiming they're all the same? Really?