As part of my ongoing quest to alleviate boredom and create a genius child, I decided to teach William (and myself) some sign language. After a three second internet search I found this website, which describes what the signs are, rather than the ever more logical approach of demonstrating them with pictures. Anyway, I managed to commit the signs for milk, change, Mommy, and Daddy to memory.
I opened and closed my fist like mad while I was feeding him (the sign for milk) and shuffled my fists around while changing him (the sign for change). Since he lacks the coordination to suck his fist with any more than 60% accuracy, I have doubts about his ability to sign, but he does enjoy it when Mommy does crazy things.