<http://schema.org/url>
<http://thenextweb.com/apps/2011/11/21/skychalk-lets-you-leave-notes-on-a-map-anywhere-in-the-world/>
<http://thenextweb.com/apps/2011/11/21/skychalk-lets-you-leave-notes-on-a-map-anywhere-in-the-world/>