Actually, it's a live feed from the ISS:
Live streaming video by Ustream
One of the latest missions from the ISS is kind of amazing. The High Definition Earth Viewing (HDEV) experiment consists of four cameras that have been attached outside of the ISS. Though temperature is controlled, the cameras are exposed to the radiation from the sun, which will allow astronauts to understand how radiation affects the instruments.
The cameras point down at Earth at all times, which makes for some breathtaking images. The feed will sometimes go down as the signal switches between the cameras, and it is hard to see when the ISS is on the dark side of the planet. If the cameras are down, the screen will be grey.
As I'm posting this, the ISS was just past the morning terminator, near the Philippines. It should fly almost directly over Chicago in 20 minutes or so. (The ISS orbits once every 92 minutes.)