Switch the toy from hand to hand to examine it.
Put something in front of his face to look at it.
Giggle, though for me this is rare...everyone can make his giggle but me.
lean up to show that he wants to be picked up.
Arch his back to help you pick him up better.
Extend his arm to bat a toy in front of him.
Do a specific "I want my mommy" cry...
Follow me accross the room, and smile when he can clearly see my face (about 6 ft).
Smile for the simple joy that someone is directly communicating with him.
Steal your heart with a single gummy grin.