Facebook remained the most popular social networking destination among U.S. adults, but users are also turning to other websites for their daily social fix .
Social networks are used by 73 percent of U.S. users above the age of 18, according to a study released on Monday by the Pew Internet and American Life Project on Monday. The study was based on 1,801 adults interviewed from August 7 to Sept. 16 this year.
