Vertical Container Gardening

What a neat, space saving concept! Vertical planters, stacked up taller than me, a foot square, water flowing down, guided by gravity. And plants tucked into the corners of each cube. We saw this in Epcot, in their "Behind the Seeds" tour of their greenhouse. They'd be good indoors and out on the patio, like for herbs or strawberries. I'd bet they'd be a nice way to create a green space divider. You can buy the containers online from Verti-Gro but they're expensive. Need to figure out how to make them myself...