First, an update: Dr. Sarah-Marie Belcastro's Home of Mathematical Knitting has moved to her new website, Toroidal Snark. Her work is a mainstay in the Geeky Knitting links, so it will take awhile to re-link.
I would also like to introduce the podcast Math4Knitters. This is mostly focussed on utilizing math in knitting, in a practical sense, but the underlying appreciation of math also comes through. Highlights include an interview with Meg Swanson (Episode 8), and a guest spot on the podcast Cast-On on fibonacci sequences (Episode 23).