I was actually reading this post about people checking out of work right at 5:01 when I came across this one about Scott's son and the train kit. This in turn led me to his post about baby sign here. Amazing how blogs are like that...
I would have to echo Scott's thoughts on baby sign. Jeannie and I have taught both of our kids some sign to get us through the tantrum years for both our sake and our children's. It is amazing how before our daughter could talk (and now our son who is learning how to talk) both would be whining about something, but then when they would come up to us would sign that they want their milk, or are hungry. What a blessing to be able to communicate with your child before they can verbalize.
To carry that a bit further, I like to think (although I have no supporting data) that this has in turn helped our daughter learn to start reading a bit early. She'll be 4 here in a couple of weeks and is sounding out (simple) words. Now while I think she is the smartest 4 year old on the planet, her Grandmother and mother are quite verbal themselves. And our daughter's older cousin did start learning to read earlier too (but he is a genius I think). :)
Anyway, if you have any doubts about teaching your young children sign language, cast them aside. I say go for it. We started at about 6 months with "more" and "up". It makes a world of difference.