I used to take this sublingual ZMA, I think it was called cyclo-ZMAss. You were supposed to crunch up the tabs in your mouth a little, then let them dissolve without swallowing. They didn't seem to work as well as plain old ZMA. (which seems odd, considering you DO just swallow ZMA)
I always thought that there would be more sublingual supps out on the market, too. But then, considering the loss from inadvertant swallowing(sp?), and then the negative feedback from people who didn't get results because of it, I'm sure companies would have a tough time with marketing.
Still, I'm sure there are quite a few things out there that would work much better in sublingual delivery, like b-12 does.(I believe?)
Someone on another thread mentioned nasal delivery for some supp as a joke, as in empty the powder into one of those nasal sprays, and Voila! straight into the blood stream. Maybe it was for a nootropic.