<http://schema.org/topics>
"features,gallery,Google,Google Lists,google plus hangouts,Google Plus Lists,How To,Lists,screencasting,Social Media,software,trending,Video,Video Lists,web 2.0,Web Apps"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2011/08/05/google-plus-record-hangouts/>