I would have thought we had reached 100 million web sites a long time ago. I think I have probably visited 5 million myself. But, according to this article by CNN, October saw the Internet pass the 100 million web site milestone. Of course, according to the aritcle less than half of those sites get much traffic and are updated regularly.
You have to get through a lot of text, but at the end of the article is a good description of where we are on the web today from Professor Rebecca Grinter of Georgia Tech’s College of Computing:
“The Web has gone from being a very straightforward thing where you put some text and perhaps some images, to being this incredibly powerful medium in and of itself. You can engage so much more dynamically, and so many more people are doing so many more things. And who knows what will come about tomorrow?” said Grinter.