We're all familiar with the Web as a source of rich and varied content. What if that content, or at least the important data within it, could be accessible not only to humans but to computers as well? It could then be sifted, grouped, sliced and diced, and served to us in ways we'd be hard-pressed or unable to achieve ourselves.
The Semantic Web is about transforming the World Wide Web into exactly that sort of system. There are several good reasons to pay attention to this idea. It's full of both technical possibilities and market opportunities. But perhaps the most compelling reason is that the primary visionary behind the Semantic Web is Tim Berners-Lee, the man who was the primary inventor of the World Wide Web. You don't need to spend more than a few minutes reading his ideas to realize that he has a clearer view of the Web's future than a thousand dot-com CEOs. (A list of essays from Tim Berners-Lee is available here.)