Baby sign language - have you tried it?

Since Christophe has been born we have been practicing signs with him, just recently he has started paying attention to them. I think he understands milk, cat and more. However on my side I am proud to say that I now know over 30 signs. To help us learn we bought 2 sets of sign cards: mocobabies and Signs and Smiles. The mocobabies cards are nicer looking but the Signs & Smiles cards are more functional. Each time we learn a new sign I mount the card up in our hallway so I can easily look at them for review. Geoff also ordered some books and a dvd about signing I will let him tell you guys about them.

Have any of you guys had success with baby signs?