Live streaming video from orbit. There are cameras inside and outside the International Space Station which you can watch live here.
Live HD Video of Earth from the International Space Station. Shows one of four cameras at a time, or a message when the ISS is out of communications range. No Audio.
HD Video. Scheduled pre-recorded content, but covers ISS events (spacewalks, media interviews, educational broadcasts) and some rocket launches live.
Live video, mainly of the station exterior but sometimes shows inside and spacewalk coverage. Audio is of communications between Mission Control and ISS.
UrtheCast also have a web stream of the ISS HDEV Payload cameras. I've listed this one as well in case the other one's offline.