Thanks to Craftlog for flagging up The Lost Art of Knitting Nancies, which in turn links to a KidsCanMakeIt article on fingerknitting.
Speaking of learning new ways to knot yarn into pretty shapes... I've tried crochet for the first time, with dubious results. I got a simple chain thingy going and produce a quite acceptable rectangle of cloth, but after that I tried to make a round shape and couldn't understand the instructions and ended up just freestyling and producing a mutant flower shape. It's back to the knitting for now and I might give crochet another go when I'm feeling more patient.