I tried some of the ones this reader mentioned, and he seems to be right:

Has anyone else noticed that the whole rightwing blogosphere seems to be down just now? I’ve tried Instapundit, Tim Blair, James Lileks, Hugh Hewitt, Bill Whittle, Michael Totten, and several others and can’t access any of the sites. By contrast, Kos, Matthew Yglesias, and Marc Cooper seem fine. Perhaps some kind of DOS action is in progress?

Note: Please don’t email me with status reports on this. I’ll be deluged by well-intentioned readers.