Big wheels keep on turnin'

I may have mentioned before that Caleb finds tummy time somewhat loathsome. Well today, he did something about it.

He's been dabbling in rolling for a while now (turning over when the mood would strike him a couple times a week) but as of today I have an officially mobile baby, fully capable of rolling from front to back and back to front, over and over again until I lose him as he rolls into the next room. (There's a lot of momentum to be gained when you start shifting that much mass around.) He's able to roll in both directions, but prefers to roll 10 feet in one direction and get himself stuck on a toy or piece of furniture instead.

Tummy time is officially over. It takes him less than two seconds to roll out of the belly-on-the-ground position I've put him in and onto his back, where he proceeds to grin up and me and kick his legs wildly, delighted at his new found decision-making abilities. He was so eager to try out his new freedoms today that I finally had to strap him into his doorway jumper just to keep him in one place while I made dinner.

Somehow I thought I didn't have to worry about this until Caleb learned to crawl. I've forgotten how quickly a rolling child can travel across a house. Any tips on how to manage two children that now move in opposite directions?