First off, let's start by stating the obvious: Without the Internet, TIC wouldn't exist and the chances of us all knowing each other would be basically zero.
Now that that's out of the way... life without the Internet for me is like life without the Sun. Well, maybe not so extreme, but pretty close. Since the majority of us probably depend on the Internet to fuel our social networks...
Though then the topic changes to "what is a world without friends," the two could very well be interchangeable, for me especially. It may not seem that big of a deal with certain sites going crazy with shallow online friendships, but there are instances when the Internet can provide deep and long-lasting bonds between people who know nothing about each other. Thanks to the anonymity (even if the other person knows your identity) that the Internet implies, it becomes easier for Introverts to approach people. Without that....
I can't see how life would be better without it, other than that my vision might still be perfect if the Internet didn't exist. Then again, I don't see how life would be worse either. If you take into account that the world we live in today, the technologically advanced first-world countries, has been designed and molded around the Internet, it would make sense then that in a different world where the Internet had not been created, that the world would have developed in a completely different direction that did not depend on an Internet? For example, today most of us rely on the Internet for information to do our homework. However, this is because teachers take the Internet into consideration when assigning homework. If the Internet did not exist, then teachers wouldn't give the homework that required the Internet to answer. So any functions that we may use the Internet for may even be unnecessary in that world where the Internet doesn't exist. But this is all speculative of course.
Anyway, I believe that the Internet was probably an inevitable development. The growing population spread farther and farther across the world begged for growth in communications and after the telephone and television, it was only a matter of time before someone attempted to combine them both (or what not). Word of mouth can only go so far...
Moving on, I'd say 99% of all my friends use the Internet on a daily basis if at all possible. And that I do know some people who don't use the Internet, but they aren't my friends exactly.
((NEXT!!! Someone else come out and post an answer!))