writes "Drawn by amenities and talent, the WSJ reports that tech firms are saying goodbye to office parks and opting for cities. Pinterest, Zynga, Yelp, Square, Twitter, and Salesforce.com are some of the more notable tech companies who are taking up residence in San Francisco. New York City's Silicon Alley is now home to more than 500 new start-up companies like Kickstarter and Tumblr, not to mention the gigantic Google satellite in the old Port Authority Building. London, Seattle, and even downtown Las Vegas are also seeing infusions of techies. So, why are tech companies eschewing Silicon Valley and going all Fool for the City? 'Silicon Valley proper is soul-crushing suburban sprawl,' Paul Graham presciently explained in 2006. 'It has fabulous weather, which makes it significantly better than the soul-crushing sprawl of most other American cities. But a competitor that managed to avoid sprawl would have real leverage.'"