If you need cash and dont mind chasing Twitter clues around San Francisco, youre in luck. A group called @HiddenCash, apparently led by a wealthy real estate developer, has decided to try a social experiment by sharing their good fortune with random strangers. They choose hiding paces around the city like the underside of a park bench or a parking meter, then cache money-stuffed envelopes labeled @HiddenCash — Tweet when you find.