NASA TV is webcasting briefings at 1630 GMT from NASA HQ and 2130 GTM today from the Johnson space centre. My experience of the last couple of days is that their streaming video servers is give up when heavily loaded. Broadcast.com/Yahoo has alternative feeds, and they support Windows Media Player. #
A good example of a blog covering the Columbia disaster. CNN’s timeline. #
NASA has a couple of mailing lists that I’ve found useful. For press releases, email majordomo@lists.hq.nasa.gov with “subscribe press-release” in the message body. For human spaceflight news, email majordomo@listserver.jsc.nasa.gov with “subscribe hsfnews” in the message body.