NY Daily News Photo Essay -- one of the best ones thus far.

Ultra Radio Photo Essay -- another awesome one.

Scripting News has been the best consistent source of news on the events I have read yet. Lots of quotes from readers and important people as well as links to relevant sites and news stories.

Metafilter has a lot of running posts with a lot of links and personal stories.

BBC Online is an amazing general source of news and for a slightly international perspective.

Blogger's search page for the words "World Trade" on all the blogs through their site.