For those who don’t know, there is something called "Baby Sign Language". The idea behind it is to give kids who are too young to speak a way of communicating. It really is handy (no pun intended). The most useful two are "more" and "done". To make the sign for "more": take your right hand and bring the fingers together so the tips touch each other (including the thumb). Do the same with your left hand. Then touch the fingertips of your left hand to the fingertips of your right hand.
It sounds more complicated than it is, but even so, most babies (I’m told) create their own variation of the sign.
Seeing what we were trying to teach him, N decided on a more fundamental approach. When he wants more food, he bangs on the table with both hands, opens his mouth and yells "Aah!".
It works surprisingly well. In fact, I’ve been thinking about giving it a try, myself.