If computers could sense the conceptual relationships between information, we humans would have to spend a lot less time sifting through the popularity-based rankings of search engines like Google to find information. That's the pie-in-the-sky premise of the Semantic Web, which some folks insist on referring to as Web 3.0.
The biggest hurdle to the Semantic Web is its reliance on metadata. The creation and maintenance of metadata has proven to be a real pain for folks trying to add intelligence to their corporate databases. In theory, metadata issues would be greatly amplified in the much larger and more diverse universe of the World Wide Web -- unless, that is, folks can figure out a way to use social networking tools like blogs and wikis to create metadata, the approach taken by the creators of the ambitious Freebase project.
An emerging standard called the Resource Description Framework (RDF), which resides on top of existing Web standards like XML and is used as a basis for data schemas, will be another key to creating the Semantic Web.
As with other Web 2.0 tools and technologies, it may be businesses that lead the way in figuring out how best to leverage them. Citigroup is among the companies mentioned in a recent Technology Review piece that are experimenting with the Semantic Web.