When I ws on maternity leave I read an article about baby sign language and the benefits, etc. I thought it was a little weird but something i definitely wanted to try with S&S. To my delight our childcare center is all about signs. I was given a booklet of basic signs to learn and do, and they used signs with S&S as soon as they started daycare, around 6 months.
I'm not sure when S&S actually started signing back, maybe around 10 or 11 months, but they are so good at it now. I really do think it gets them less frustrated beacuse they can tell me when they are hungry, thirsty, want more, etc. They now also say teh word along with the sign so that takes care of the "it'll delay their speech" worry I had. And it's just so darm cute! We only do the basic baby signs, but I think those are the important ones anyway. Sometimes Sahil will sign something, and I have ask the teachers or look it up on the web to figure what he's signing :) That happened today...he wanted to color and pointed to the drawer and signed "please." I thought he was wiping his hands on his shirt though. Marian let me know that means please :)
My point is - I recommend baby signs! At least the basic ones. Signs that we use include: drink, eat, more, help, stop, water, thank you...and please.