Experian Hitwise just reported that Facebook climbed over Google’s back to take over the number one spot on the U.S. list of most visited Web sites for the week ending March 13. Facebook’s market share also increased by 185 percent from the same week in 2009. Google, in contrast, only jumped its visits YOY by 9 percent.

Taken together, 14 percent of all US-originating Internet visits went to one of these two massive online players.

Another interesting Hitwise report looked at how much Twitter, Facebook and Google News drove users to news and media Web sites. Twitter.com accounted for 0.14 percent , Facebook drove 3.65 percent, and Google News only delivered 1.27 percent.  The Huffington Post got the most traffic from Twitter users who were looking for news and media sites. The next nine, from the highest-trafficked on down, were CNN.com, The New York Times, People Magazine, Google News, Drudge Report, Digg, The Weather Channel, MSNBC and Yahoo News.