
Facebook chief Mark Zuckerberg talks about Timeline at a developers conference Sept. 22 in San Francisco. Users can share their choices of music, movies, games and news sources with their friends as part of what the Facebook website describes as a new way to "tell your life story with a new kind of profile." (Associated Press)

** FILE ** A photo of Rep. Gabrielle Giffords posted to her public Facebook page by her aides on June 12, 2011. The photos were taken May 17, 2011, at TIRR Memorial Hermann Hospital, the day before she had her cranioplasty. (Associated Press/Giffords Campaign)

The most recent photos taken of Rep. Gabrielle Giffords (left) since she was shot were posted to her public Facebook page by her aides on June 12, 2011. The woman in the background is her mother Gloria Giffords. The photos were taken May 17, 2011, at TIRR Memorial Hermann Hospital, the day before she had her cranioplasty. (Associated Press/Giffords Campaign)

Israeli troops search for gaps in the fence along the border between Israel and Syria near the village of Majdal Shams in the Golan Heights, Monday, May 16, 2011. Mobilized by calls on Facebook, thousands of Arab protesters have marched on Israel's borders with Syria, Lebanon and Gaza on Sunday in a(...)

Israeli soldiers fix the border fence between Israel and Syria near the village of Majdal Shams in the Golan Heights, Monday, May 16, 2011. Mobilized by calls on Facebook, thousands of Arab protesters have marched on Israel's borders with Syria, Lebanon and Gaza on Sunday in an unprecedented wave of(...)

An Israeli soldier covered in a prayer shawl prays as Israeli troops gather near the border fence between Israel and Syria near the village of Majdal Shams in the Golan Heights, Monday, May 16, 2011. Mobilized by calls on Facebook, thousands of Arab protesters have marched on Israel's borders with S(...)

**FILE** President Obama and Facebook CEO Mark Zuckerberg take off their jackets at Facebook headquarters in Palo Alto, Calif., on April 20, 2011, before their joint town-hall meeting to discuss reducing the federal deficit. (Associated Press)

Many high schoolers might favor Adriana Papell dresses for prom night, but Facebook is helping them call "dibs" online, assuring no duplicates. (Lord & Taylor Associated Press)

Patrick Pichette, chief financial office of Google, claps after an announcement at in Kansas City, Kan., Wednesday, March 30, 2011. After seeing Facebook pleas and flash mobs, and even cities temporarily renaming themselves "Google," the search engine giant said Wednesday it has chosen Kansas City, Kan., as the first place that will get its new ultra-fast broadband network. (AP Photo/Orlin Wagner)