From CNET News:
According to the blog trackers at Technorati, a company that indexes and searches blog postings, the number of blogs online is doubling about every five and a half months .
As of Monday, the company is
tracking more than 27 million separate blogs around the world, or about
60 times what was online three years ago. About 2.7 million of those
blogs are updated at least weekly, with about 1.2 million total posts
appearing per day, Technorati founder David Sifry said in his "State of
the Blogosphere" post on Monday.