It's a good thing Gavin Newsom checks his Twitter feed during meetings. Otherwise, San Francisco's mayor would've missed a life-changing missive about ... potholes? "It really made me wonder," he says. "What if we used social media to make our city services work better?" That stray tweet led to the city's first-of-its-kind Twitter account (@SF311), which encourages residents to send queries and messages about nonemergency issues. But it also underscores the city's open-source stance on government. Just as Google, Facebook, and Twitter released their programming interfaces to app makers, San Francisco opened its arsenal of public information -- train times, crime stats, health-code scores -- to software developers. "There's a tremendous amount of tech talent here," Newsom says. "We'd be fools not to leverage it." To date, more than 140 data sets have been liberated, spawning roughly 30 smartphone apps, such as Crimespotting (browse interactive city-crime maps), Routesy (see real-time train schedules), and EcoFinder (locate the nearest recycling spots). But San Francisco's open-source stance doesn't stop at the city limits: In February, it launched an idea-sharing site, which blueprints everything from citywide health insurance to banning plastic bags. And in March, it released the API for its 311 city-service center. Boston; Los Angeles; Portland, Oregon; Seattle; and Washington, D.C., have already pledged to adopt the new standard.