PostSecret's premise is old by now — anonymous people send in secrets on postcards that are scanned and posted online. But the endlessly fascinating array of responses makes this blog worth a return visit. PostSecret has even branched out beyond the Web. After an anonymous illegal immigrant posted pledging to jump off the Golden Gate Bridge because the person "didn't belong," thousands of fans of the blog joined a Facebook group to urge the person to reconsider. Some devotees even held a rally at the bridge. Was the post real? Did the person see the response? The fact that there is no answer to these questions only adds to the blog's mystique.