Word Bursts Could Help Refine Web Searches:

A besieged e-mail inbox prompted Kleinberg to design the new system. While trying to filter his mail, he theorized that whenever an important topic arose, keywords related to it would show up in messages with increasing frequency. As a result, searching for words whose usage increased dramatically and quickly—or "burst"—could help identify significant topics and provide a way to categorize messages. Kleinberg devised a search algorithm that analyzes both the number of times words appear and the rate of increase in their frequency over time.