Now a bit of terminology: "Neighborhood search" is the familiar search in the web page footer. For the now useful searches reached from the wiki page footer we will refer to the various choices as "footer link search", "footer site search" and "footer item search". Each has nice properties. chat 
I would like to draw special attention to "footer item search" which relates pages that share items in what is essentially an undirected hyperlink.
This morning I wondered, how is each page of the Long Chain of Pages game thus linked with the federation. Most pages aren't since they were written from scratch. But in upper floors of the game I drew pieces from prior work that showed wiki capabilities well. That was the point of the game. But now know, if you like the game, and wonder from what it was written, now you can answer that question with footer item search.
This is a style of linking that we should encourage. It might just be the best possible citation: copy a good paragraph from some other important work and then wordsmith it to fit into your writing. The source is never forgotten but your contribution is obvious too.
I would argue that this captures the best of two worlds, informal and academic learning. Wikipedia sought respect by laborious academic style citation from respected sources and thereby choked most of the creativity out of the creative commons license we both employ.