I think it is so amazing that babies can learn sign language. Babies can sign when they are hungry, wet, and even say thank you. However, as much as I think it's amazing, I have never taught my boys sign language (Yes, I know mother of the year.)
Despite my poor mothering skills, Collin has developed his own sign. I noticed it a month ago when I gave him food. If he really likes a certain food, he taps his hand on his high chair *pat pat pat pat.* If we are playing and something makes him laugh, he taps his hand on the floor, *pat pat pat pat.*
I have come to the conclusion that *pat pat pat pat* means, "I want more, please." (He had to throw the last pat in just to be polite.) If he REALLY likes a food he pats very loudly *pat PaT PAT PAT.* The louder the pat, the better he likes the food.
I love his little sign, and how it gives me a window into his little mind. Honestly, I origianly thought *pat pat pat pat* meant "I love you so much mommy. You are the best cook ever. This is so delicious," but I thought that was a bit of a stretch.