"I'm a candidate for governor of California because I know we can do better," Newsom says looking straight into the camera in his YouTube announcement video.
The two-term mayor will tour Facebook's headquarters later this afternoon. Newsom has already being "followed" on Twitter by nearly 275,000 people as he has been criss-crossing the state for townhall-style meetings in the last few months. His campaign hopes his new media announcement will directly reach a half-million people by the day's end.
Newsom is the second Democrat to officially join what's expected to be a crowded Democratic field in 2010 to replace the termed-out Gov. Arnold Schwarzenegger.
Lt. Gov. John Garamendi is an announced candidate and Attorney General Jerry Brown is widely expected to run. Other potential candidates include Los Angeles Mayor Antonio Villaraigosa and U.S. Sen. Dianne Feinstein.
Garamendi, however, is also considering running for a soon-to-be vacant Bay Area congressional seat.
On the Republican side, there are three major contenders exploring runs: former Rep. Tom Campbell, Insurance Commissioner Steve Poizner and former eBay CEO Meg Whitman.
Photo: San Francisco Mayor Gavin Newsom speaks to over 150 people gathered in the library of Redwood High School in Larkspur, Calif. on Monday, December 1, 2008. Credit: AP/IJ photo/Alan Dep.