The reason they did all this isn't that they're planning on floating balloons all over the globe, but as an experiment and in order to create an inexpensive toolkit for people to collect their own mapping data. You'll need about $100 and a camera, but then you'll be able to take pictures from a thousand feet in the air and stitch them into one big one.
You can buy one here. It includes a large reusable balloon, a thousand feet of line, special gloves and various other necessities for getting your camera up in the air.
Wooo! Thanks so much for the write-up, Devin. And a big congratulations to our non-profit partners over at Public Laboratory!