I’m still waiting for online social networking to take off. I’ve been on LinkedIn for many months and, while my network has grown (342,300+), I’ve received maybe two messages and never really accomplished anything.

So I was intrigued by a story in The Register about the launch of a Web site called Yelp. Started by Paypal founder Max Levchin’s incubator company, Yelp helps people find stuff they want by using their existing contacts—friends, families and colleagues—and their e-mail addresses. Let’s say you want to find a great new seafood restaurant in San Francisco. You’d enter that request and the e-mail addresses of friends whose opinions you trust. They’d get an e-mail with the request and respond. If they don’t have a recommendation, they can forward the e-mail to their friends. When somebody responds, you get an e-mail with a link to the site where you can read the replies. The replies link to back-end services, like addresses and maps. Since these searches are saved, the service grows into a comprehensive source of such information.

The Register article gets into some fascinating discussion of the problems with social networking and how Yelp avoids them. But my mind turned immediately to the issue of knowledge sharing inside organizations. How hard could it be to set up Yelp inside a company? Instead of asking where I can find a great mint julep, an employee can ask if anybody has experience with a certain kind of work, forwarding the question to people he knows via the intranet site. Answers eventually come from people he’s never heard of as those who get the message forward it to others they think may know the answer. All of it is managed by a database and retained for future reference. It’s so much simpler than those multi-million-dollar knowledge systems that never seem to do any good.