My kids are both in L-O-V-E with the mobile on Jason's crib. When I turn it on, Jilly will come RUNNING from the other room, then climb her bed and just stare at it.
Jason will get all smiley when I turn it on too. He's really loving watching the animals dance around.
And Jason's other most recent favorite discovery: his fists. He is always chewing on them and slobbering all over everything else, most often me. ;-)
And just because it was so exciting: Jason slept 8 hours all by himself in the cradle last night!!! WOOHOO!! He hasn't ever done that. It was awesome for Mama!! I only got up once to pop his pacifier in, and he didn't make another noise for 6 more hours. I doubt it will continue, but hey! I'll take it when I can get it. :-D