Peter Norvig, the director of research at Google, estimates the Internet currently holds about 100 trillion words. Since he used to be a NASA Ames researcher he may be one of the best people to make that guess.

He also made the claim that the Internet is growing about 10% to 20% per month, but since some other parts of the Internet are dying, it's not really that big overall. At that rate, who knows how big the Internet could be in another 10 years. It's like a big balloon, getting bigger and bigger and bigger. How many zeros is that anyway: 100,000,000,000,000. Is that right?