Even before the current hubbub about social networking as a source of insider information and tips, it has been possible to contribute — and read — reviews of products and services via sites like epinions.com and amazon.com. In fact, the input of ordinary people can build credibility for retailers — or discredit them — and is empowering for both contributors and those who read their reviews. Wikipedia, the on-line encyclopedia, lets anyone with a passion for a subject become an instant expert — at least until his or her entry is challenged and/or edited by someone else.

With its 2 Cents Project, the San Francisco Chronicle hopes to create a pool of citizen-journalists “who agree to be accessible to The Chronicle via e-mail to provide commentary on the news of the day and share their expertise and experiences with our readers.” The project is open only to residents of Northern California (with the exception of Chronicle employees and members of other Bay Area news organizations). Priority is given to those who live in Alameda, Contra Costa, Marin, Napa, Santa Clara, San Francisco, San Mateo, Sonoma and Solano counties. But it’s a model we’d like to see replicated elsewhere.

Here’s how it works:

Two Cents correspondents get a shot, says the Chronicle:

• When news breaks and we need to gather input from people but are constrained by tight deadlines.

• When traditional means of finding sources for stories fail.When either of these circumstances occur, we e-mail requests for information or commentary to our correspondents and ask them to respond or to forward our e-mails to people they know who are able to respond. Sometimes we contact people who respond to our e-mails and interview them for stories. Sometimes we run a column of correspondents’ comments, along with their name, photo and name of the town they live in.

The new science of predicting success also draws on ‘the collective intelligence” of groups of people. The Hollywood Stock Exchange, for example, is adept at accurately predicting box office success and Oscar nominations. “Nobody knows anything,” concludes James Surowiecki, author of the article (The Science of Success), “But everybody, it turns out, may know something.”