Perhaps the most visible manifestation of the post-hurricane outpouring of good feeling has been Sandy Coworking, an effort to make desks and Wifi available for anyone who need a place to be productive. Almost as soon as the clouds parted, anyone with a working office was offering to host the displaced. Staffers from Buzzfeed took up residence in Heart’s cafeteria. Kickstarter moved in with Boxee. Venture capitalist Charlie O’Donnell suggested the hashtag #sandycoworking for those seeking and offering space; as the offers began flying fast and furious on Twitter, Mr. Hidalgo hacked out a platform for anyone to list what they had.