I did not know there was such a thing!....thanks Slim!...My daughter is a yoga teacher, and my hubby and I go to two classes a week (not hers, she lives in another city)....so I KNOW these would be great for classes. I'm making some!!! In fact, I'm going to rip out my just-started socks and make these instead. Thank you. I just went and got the pattern online, copied it out.
MerigoldinWA: it's not cuz the feet get too hot (although some people say theirs do...). Rather: it is so you don't slip sideways on your mat or the floor, and can hold your posture more firmly with good feet-grip.