There is a lot of hype surrounding the real-time web, and much of the feeding frenzy reminds me of the RSS space four years ago — though there is a lot of potential, there is also a lot of noise. How do you navigate through it all and which developments should you be paying attention to? What are the emerging trends for companies and entrepreneurs to watch for? Here are four real-time web trends that I’m tracking.

Over the past four years, the use of online classified ads by U.S. adults has doubled, according to a study from the Pew Internet and American Life Project. Specifically, 49 percent of adult internet users say they’ve accessed an online classified, compared to 22 percent who did so four years ago. And on an average day, 9 percent of web users go to an online classified, up from 4 percent in 2005.