Facebook Soars, MySpace Shrinks and Twitter Slows

New data from Hitwise highlights the dramatic reversal of fortunes in the social networking world. Facebook's share of U.S. traffic to social sites has grown nearly fourfold in the last year, to 58.6% from 19.9% as of September. Heading in the opposite direction is MySpace, which has seen its share tumble to 30.3% from 66.8%, a 55% plunge.