Twine, a new Web-based application from San Francisco startup Radar Networks, helps people keep track of personal data, including e-mails, documents, photos, videos, and visited Web pages. But its artificial-intelligence algorithms also help categorize that data, sometimes finding surprising connections in disparate content. It is one of the first commercial applications to take advantage of standards developed by the World Wide Web Consortium for the Semantic Web, an envisioned network that will automatically classify and sort information.