Who's Your Mayor? Philanthropy Meets Foursquare | Social Enterprise

Who's Your Mayor? Philanthropy Meets Foursquare | Social Enterprise: "Blanketing BART stations in San Francisco since mid-June are public service ads urging passers-by to use their cell phones to 'drill the oil industry.' Another Twitter campaign? Guess again. Think Foursquare, the new mobile social network which a number of nonprofits are using to drum up some money and a crowd of supporters -- online and off."