All the recent news about Facebook — from its founder being named Time magazine’s Person of the Year to Goldman Sachs placing a $450 million bet on its future profitability — makes it clear that social networking platforms are hot commodities. It’s also clear, however, that not all social networking platforms are created equal. So, while Facebook continues to attract hordes of new users and piles of cash from investment bankers, platforms such as Foursquare and Gowalla — known generically as “location-based services” — are living a lonelier existence.