Panduit dropped off a new toy... err tool today. It's a sample of their new blanking curtain. Instead of a slew of 1U or so panels to attach to a rack, it's 4U that expands up to 45U. Of course it only works if you are blanking contiguous areas.
It was a breeze to install and it is supposed to work in both square and round hole racks. Changing the size as you add servers to the bottom of the rack is a tool less 10 second procedure. All in all, I think it's a great new product for data center air containment.