When you tag photos in flickr with OSM metadata like ‘osm:way=30089216’ the squirrels will busily work to figure out what you’re talking about and link over to OSM. See this example and scroll down to look at the machine tags and stuff on the right. It figured out the building from the road it’s on and the name of the photo. Magic.
Also, check out the flick blog post on the subject.
Funny how the flickr guy cites the node scheme: “a single _geospacial_ point” 😀