There are several answers to this question. It also depends on exactly what you mean by the net or web. There are several different ways of defining this for counting purposes. Estimates, at the end of 1998, run between 50 million and 150 million. Every number you will see is an estimate.
Every number is soft.
A whole damn potful. That's technical jargon for a lot. Whether it's fifty million or one hundred fifty million, it's still a lot of people. Let's not hyperventilate just yet, though. Remember that one third of the world has yet to make its first phone call.