Twitter's San Francisco headquarters located on the 4th floor of 539 Bryant Street | Twitter's San Francisco offices on 539 Bryant Street |
A Twitter profile | A blueprint sketch, circa 2000, by Jack Dorsey, envisioning an SMS-based social network |
American actor Ashton Kutcher is the most followed user on Twitter. | The Twitter fail whale error message. |
Oprah Winfrey's first tweet. | The Twitter mascot. |