<http://schema.org/url>
<http://thenextweb.com/apps/2011/03/08/foursquare-vs-unsubscribe-two-ceos-duke-it-out-over-twitter-and-youtube/>
<http://thenextweb.com/apps/2011/03/08/foursquare-vs-unsubscribe-two-ceos-duke-it-out-over-twitter-and-youtube/>