For social networks that will explode in popularity in 2012, Temple Fox School of Business social media expert Steven L. Johnson has his money on Pinterest, a site for organizing and sharing images found online. "Pinned" photos can be posted to personalized, themed "boards," which other users can follow. The site taps into the need for what Johnson calls "content curators" with shared interests. "It's not just about finding sources of info, it's really about finding people you can trust that can sort through that information for you," said Johnson, who calls Pinterest "the first virtual social scrapbooking."