We've been working on the baby signing for a while now. The one we use most frequently is the sign for milk, though I also use kitty, more, bath, and finished as much as I can. For about a month now I've been sure Carter understood the milk sign. When he seemed hungry and I signed "milk" to him, he would smile and get excited.
About a week ago, I was getting ready to leave and Michelle (his nanny) was holding him. He made a whining noise and held out his arms towards me and signed "milk" with both hands. Michelle signs with him too, and we both saw it at the same time and went "OMG, look at him!". So I sat down and nursed him again before leaving.
He will occasionally sign "milk" while nursing, but he hadn't used it to communicate again until this morning. Doug was cleaning, I was sitting at the table paying bills, and Carter was playing on the living room floor. He was starting to get fussy, and I glanced over at him -- and he was lying on the floor, looking at me and signing "milk"! So I jumped up and went to pick him up and nurse him.
It was so cool to think that he was able to tell me that's what he wanted. We'll see if he starts doing it more regularly now. This totally motivates me to do more signing with him! I love the idea that he will be able to communicate with us a little bit long before he starts talking. :-)