Founded in late 2006, Twitter provides a communication tool that lets users post 140-character-or-fewer updates on their current activities or thoughts, noteworthy links on the Web, or public conversations. Twitterers can be found all over the world, posting updates 24 hours a day, but this photo essay will take you inside the Twitter offices, in South Park, San Francisco, where programmers try to turn the constant connection provided by the Web and cellular networks into a tool that some people find indispensable.

Twitter cofounders Evan Williams (above right) and Biz Stone discuss upcoming changes to the company's service in its office's main meeting room. Williams and Stone are veterans of the first dot-com boom and note that starting a company today is much easier: a product can be developed by fewer people and rolled out faster. This has led to a mass of startups that release products in "limited beta," a period in which early adopters test features, and startup engineers watch how the infrastructure holds up. Today's startups can wait longer before they are funded, maintaining their autonomy and ability to change course. Twitter, a side project spun out of Odeo, Williams's former podcasting company, was prototyped in a few weeks. Stone maintains that the idea behind Twitter wouldn't have fired up a room of venture capitalists: before seeking money, the company had to show the service in action.