Speech therapy?

Ok, I'm being totally neurotic here.
Eli is so verbal these days, but I'm starting to detect a lisp.  Is it possible in kids this young?
He's not really saying words, but just the way he babbles makes me think that I'll be signing him up for speech therapy.  After all, no one wants a Cindy Brady lisp, right?

He definitely understands more than he says.  We had been watching a Baby Einstein video (the only thing he's ever watched on TV) on Signing with your Baby.  I think they teach about 20 words to sign with your baby.  The only sign he's using?  The one for "milk" - which he does when he wants to nurse.  He doesn't use "mommy" or "daddy" or even "bath"!  He just wants the boob.  I guess weaning isn't coming anytime soon.  I'll just be comforted by the fact that when I say "Ba dau" (where's daddy?), he turns and looks for his dad.  When I ask "Dua nao thuong Ngoai" (who loves grampa?), he raises his hand.  When I say certain phrases from his books, he'll go bring me that book.  He knows a lot.  I'm just waiting for the day when he actually responds with real words., like when I ask "Met chua" (tired yet?) and he says "Chua!"

Btw, his 1st birthday is tomorrow and I am so excited!!