Here's a quick video of Mr. Jack Jack crawling (well, scooting) around the living room.
Earlier he had been on his way to crawl through the exersaucer and instead pulled himself up into a seated position! That was the first time I had seen him do that! He almost does it in this video but then gets distracted and decides to keep going.
He's a little stinker - always going faster when I say "I see you!!" :)