There is a booth at Grand Central Station, part of their holiday fair, that is selling Calorimetry-like hats. These are done in bulky or nubby yarn. I don't think they are as nice as the original but certainly they seem to be a knock-off. I don't know what the price is but I have been there twice and saw people buying them. Ellen
Today in Manhattan, it was really cold, and I saw several hats that looked like handknits. One had spiral ridges of knit-purl (maybe 4 rows knit, 4 rows purl) in a yarn something like Noro Silk Garden. Very nice. Also several handknit chullo-style hats (along with acres of machine-made chullos). And a girl's cap knit of two strands of wool, brown and yellowish-tan.