Living in the UK, I don’t have easy access to NASA TV except through the on-line web streams. You can view NASA TV directly from the NASA website, but if you look around you can find better quality stream out there. You could try this one which is a blistering 1200kbps, which is too fast for my domestic net connection or this one at a more modest 500kbps.

Update (16.10.08): I’ve just tried both these streams and they still appear to be live! Clicking on the link doesn’t always work, I have to “copy link” and then paste it into the “open URL” menu in windows media player. If you know of any other streams, please post them in the comments!