Sam's turned into quite a book worm lately. I've been reading the same books to him for months, usually in wildly animated voices with elaborate gestures, and never got much reaction from him. But yesterday, he started whipping his little pointer finger through the air while making a "zzzzz" sound as soon as we turned to the "bumble-bees love buzzing" page in Mommy Loves Her Baby/Daddy Loves His Baby (one of my favorites). Later, while reading Bear's Big Blue House (a birthday present from grandma), he designated one of Bear's lower kitchen cupboards to be the "ba-bage" (garbage). He then mimed washing his hands over Bear's kitchen sink. (OK, so I let him play with garbage. At least he knows to wash his hands afterward!)
It's gratifying to see things clicking for him.