I have temporarily removed Neil Gaiman's weblog from my catablog. His server is infected with the Nimda worm, which means that anyone running Internet Explorer version 5 will get infected if they view his site.
I am very thankful for the fact that I use Opera (and Apache). It scared the crap out of me when Opera opened up a window with Nimda in it, but that's a hell of a lot better than executing it invisibly, which is what IE5 would have done.