Because it's the 21st century and about time we were able to watch our own home planet any darn time we want, NASA has bestowed on Earthlings the gift of live video of Earth, as taken from the International Space Station (ISS).
In NASA terms, this really cool thing is actually called High Definition Earth Viewing (HDEV) and is mounted on the External Payload Facility of the the European Space Agency's Columbus module on the ISS. Parts of the HDEV experiment were created with the help of high school students, some of whom will assist in operating the experiment as well.
According to NASA, the experiment is assessing what effects, if any, the space environment has on camera equipment and video quality, which may impact the choices of cameras in future missions. Watch the "experiment" in action below. The HDEV uses multiple cameras for the Earth view, which it switches between. During camera switches the screen will be gray, so be patient. The ISS goes through darkness during its orbit, and the video feed will be dark during those times.