<http://schema.org/topics>
"apps,brightkite,Checkin Mania,Foursquare,google maps,gowalla,location based social networks,Mashable,news,social games,Social Media,social networking,yelp"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2010/03/30/checkin-mania/>