But seriously, I've been playing around with Wikidata's Query Service[0]. Here's an example...[1], the example asks, "What is `nature' a part of?" (Once you click through the URL shortener you can click execute to run the SPARQL[2] query. SPARQL's a W3C recommendation, sort of like SQL but for triplestores, but its details are not readily graspable I think.)
It seems like Google's Knowledge Graph is based on Wikidata? I used to think the Semantic Web was always going to be a decade away but now I think that it is going to play a large part in the near future of the web though if you pushed me to explain my change in reasoning I don't think I'd be able. What we need are Semantic Web Browser, no idea what they'd look like though :(
Here is Wikidata's table of properties from which it builds up its entire knowledge graph[3]. I think it's fascinating.
[0] https://query.wikidata.org/
[2] http://www.w3.org/TR/sparql11-query/
[3] https://www.wikidata.org/wiki/Wikidata:List_of_properties/Su...