Don't miss danah boyd's post from a few days ago on patterns she's observed in an analysis of Technorati data on a random selection of 500 blogs. Among her observations:

• When bloggers link to another blog, it is more likely to be same gender.
  
• Blogrolls seem to be very common on politically-oriented blogs and always connect to blogs with similar political views (or to mainstream media).
  
• Few LiveJournals have a blogroll but almost all have a list of friends one click away. This is not considered by search tools that look only at the front page.
  
• Links indicate no weight, no valence, no attributes. I know Technorati has asked folks to indicate positive/negative in their links or to use nofollow, but few do this. And even if people did, that kind of articulation is a social disaster
  
• On LJ and Xanga, there’s a gender division in blogrolls whereby female bloggers have mostly female “friends” and vice versa.