It's not news that the offices of big, multimillion-dollar tech companies like Google and Facebook have fueled the fervor across industries for open-plan offices with ball pits, slides, and other childlike accoutrements. Though these elements are meant to encourage a sense of playfulness and, we'd guess, foster creativity, some have argued that this kind of big-kid decor is, well, infantilizing. In New York, the professional social media network Linkedin's HQ (in the Empire State Building, no less, a symbol of commerce and industry in the city and state) has a speakeasy. In London, a creative design and branding agency filled an open space in their office with a temporary ball pit to encourage a little fun. And at Facebook's NYC offices, designed by Frank Gehry, you can play table tennis.