Technorati has been tracking the blogosphere, or world of weblogs, since November 2002, and I'm constantly amazed at the growth over the years. The blogosphere has been doubling in size every 6 months or so. It is over 100 times bigger than it was just 3 years ago.
...In January of 2004, the blogosphere was doubling at a rate of once ever 120 days, which is about once every 4 months. By July of 2004, the blogosphere was doubling every 180 days, or about once every 6 months. Today, the blogosphere is doubling in size every 200 days, or about once every 6 and a half months. That means things have slowed somewhat - the rate of doubling has increased by about half a month to once every seven months.
As of July 2006, about 175,000 new weblogs were created each day, which means that on average, there are more than 2 blogs created each second of each day.
Lots more with pie charts, graphs and lists at the Technorati link. It's looking more like a chain letter than ever before. Stick around a year or two and we'll run out of people. Like bathrooms, cars, televisions and socks we'll all need several just to be ordinary.