Robbie has a few new skills these days. He still can't (won't?) crawl, but he doesn't really need to. He's figured out how to bounce across the floor on his butt. The video below was taken last week. He's got a lot faster since then. The first video also shows him transitioning from sitting to his belly. He's been working on that skill for a while. There were lots of head thumps for a bit, but he seems to have it down now.
He also is clapping and waving. He's been doing both for a little while now, but he's now getting much more dependable about it. These days you can say "bye bye" and he waves. Often while staring at the door wondering who's leaving. And almost any time you say "yay!" or someone on the TV cheers, he joins in.