I got a sketchpad and am fooling around on it, practicing sketching motions and emotions. Motions are easy, emotions are hard. So far, this is my favorite from the motions sketches:
If you're looking for some mathy updates, perhaps you should consider reading Geoff's very technical blog. He recently put up an implementation of the Rotating Calipers algorithm for finding the minimum bounding rectangle around any polygon. (The algorithm finds the best rotated rectangle, not just the best right-side-up rectangle, which would have been too easy.) His tech blog is super dry like the stock market books that he reads in his leisure time, but he likes it that way. :) He says he just wants to dump information on the internet to facilitate other people who might come across the same issues, so reader-friendliness isn't one of his main concerns.
Anyway, if you read through his implementation, you'd see that there's a lot of vectors math in there. It's neat... He's a computer programmer who actually uses high-school math on a regular basis to solve problems!