<http://schema.org/topics>
"Apple,iPad,apple lists,arcade games,duck hunt,features,frogger,Gadgets,Gaming,Games Lists,ipad games,iPhone,iPhone Apps,iPhone Resource Lists,Lists,Mobile Lists,pac-man,pong,pop culture,retro games,space invaders,Tech,trending"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2010/06/27/arcade-games-iphone/>