That's fantastic!
We've been trying to teach our little one to sign too (she has speech delay and cerebal palsy so unable to use right hand so some of her signs are improvised) - she can do "more", "pig" (thanks to Justin from Something Special) and "eat" (she uses same sign for eat, biscuit, food).
She's also learning "orange", "nappy" (we're using toilet sign) and "finished".
Over the past few weeks she's started to string signs together to make a short sentence - so she'll point to my laptop, do 12345 on her fingers and then sign "more" ... she asks for the fish alive nursery ryhme video on youtube lol!
We've been practising nursery ryhme signs too - so she'll do twinkle twinkle by opening and closing her left hand, she's got signs for incy wincy spider and fish alive. So although she can't talk I suppose she can say quite a few things ... haven't really thought about it like that before.
....sorry to jump on your thread!