Glenn Reynolds has written a nice essay on how Google would have been inconceivable 10 years ago. Here's an excerpt:

Just try this thought experiment: Imagine that it's 1993. The Web is just appearing. And imagine that you - an unusually prescient type - were to explain to people what they could expect in the summer of 2003. Universal access to practically all information. From all over the place - even in bars. And all for free!

I can imagine the questions the skeptics would have asked: How will this be implemented? How will all of this information be digitized and made available? (Lots of examples along the line of "a thousand librarians with scanners would take fifty years to put even a part of the Library of Congress online, and who would pay for that?") Lots of questions about how people would agree on standards for wireless data transmission - "it usually takes ten years just to develop a standard, much less put it into the marketplace!" - and so on, and so on. "Who will make this stuff available for free? People want to be paid to do things!" "Why, even if we start planning now, there's no way we'll have this in ten years!"

Actually, that final statement is true. If we had started planning in 1993, we probably wouldn't have gotten here by now. The Web, Wi-Fi, and Google didn't develop and spread because somebody at the Bureau of Central Knowledge Planning planned them. They developed, in large part, from the uncoordinated activities of individuals.