The most fascinating blog to emerge from Hurricane Katrina is Michael "The Interdictor" Barnett's blog, in which he documents what's happening in New Orleans from the 10th floor of a downtown New Orleans building. Barnett is the "crisis manager" at the domain name registrar DirectNIC, which shares its space with its sister company, Zipa, and in a prior life, he was a soldier in the U.S. Army Special Forces seem to have served him well. He's been helping keep the company's servers up and running since the start of the storm last week and blogging about his experience. It's a fascinating read, and I suggest you read it from his first Katrina entry, which simply reads:
Hmm. This could actually be a nasty storm.
Wired has a short piece on Barnett.