Caspian is obsessed with bottles and cups. I had my empty 2-liter with me when I walked in on a diaper change last night. He wanted that bottle, so I let him play with it -- he knew just what to do!
Last night in his bath, Caspian sat up and splashed for three or four minutes before we started washing him. You can see the evidence of his exuberance in the waves and on the mirror/wall next to the tub.
Any time he started to wobble, he'd grab the side of the tub instinctually. I was nervous, but he never slipped!