SAN FRANCISCO—SweetSpace.com, the new social networking start-up from Caltech wunderkind Devin Preston, launched Wednesday with the stated intent of bridging the gap between Facebook and Facebook. "The easiest way to explain SweetSpace is that it's essentially Facebook meets Facebook," said Preston, noting that like Facebook, SweetSpace.com will allow its members to communicate publicly by having a wall that people can post to, but, like Facebook, members will also be able to message other users privately. "Ultimately, the goal of SweetSpace is to be Facebook for the Facebook generation." Preston added that the new site will have pri­vacy issues comparable to Facebook, but assured users it will deny them, like Facebook.