Funding: Self-funded by Obvious founder Evan Williams.
If small talk can translate into big numbers, then Twitter-developer Dorsey might have a hit. Twitter's Web site poses a simple question: What are you doing? Since mid-2006 summer, more than 80,000 U.S. users have answered, broadcasting quick updates about actions as quotidian as ice-skating and making dinner. Users send in information via text message, instant messaging software, and the Web. “The goal was to get you away from the computer,” says Dorsey, who dropped out of New York University and left his job as a programmer at a taxi- and courier-dispatch service in 1999 to move to San Francisco.
Lesson learned: “Stay open,” Dorsey says. When Twitter launched, the software required a phone number to join. Once he allowed users to sign up using their e-mail addresses, expanded the service to include IM, and added a programming interface for developers, the number of users and posts shot up. “All made Twitter more approachable by a greater number of people,” he says.