Crawling or walking?

I turned around on Sunday to find the baby standing up in the middle of his play pen holding onto nothing but a length of plastic chain links tethered to the edge of the pen (I call it his "kennel"). He was just standing there balancing and grinning at me while looking extremely pleased with himself.

I'd call that definite progress on the walking front.

But there's also this crazy crab-scoot he's been doing lately that might be described as a form of crawling, and he definitely can get wherever he wants to go:

I dunno whether the scoot counts as crawling first or if he's going to just go directly from scoot to walking, but either way, we need to baby-proof the house STAT! He's already decided that he loves climbing on the Roomba and pulling DVDs off shelves. Doubtless bobby pins in wall sockets will be next.