In a post called 'Linkology: picturing blog relationships':
"There are upwards of 27 million blogs in the world. To discover how they relate to one another, we’ve taken the most-linked-to 50 and mapped their connections. Each arrow represents a hypertext link that was made sometime in the past 90 days. Think of those links as votes in an endless global popularity poll. Many blogs vote for each other: “blogrolling.” Some top-50 sites don’t have any links from the others shown here, usually because they are big in Japan, China, or Europe—regions still new to the phenomenon."
There is a graphic representation of these blog linkages available as a pdf download.
Definately a snatch for those involved in blogging networks.