The Wall Street Journal Online has a fascinating look at persistent search technologies that enable individuals or institutions in need of real-time information (e.g. day traders and hedge funds) to watch the Web on a minute-by-minute basis for market-moving news or a "spike in online chatter."

One of the companies mentioned is New York-based PubSub, which picked up news about the Indonesia earthquakes minutes before the information appeared on the U.S. Geological Service's own Web site. Another is Monitor110, which provides persistent search services to Wall Street investors looking for a competitive advantage.

Before you rush out to buy stocks or make life-changing decisions based on a willowy wisp o' information, keep in mind one important caveat: "Only reckless investors would trade a stock based on information contained in a few blogs or message boards, a domain rife with short-sellers eager to spread rumors."