There should be a subset of the game googlewhacking (wherein one tries to find a word or word combo that leads to only one site). Instead, my variant would be that you look for a tag at flickr that only leads to one image.
Flickr: Photos tagged with logorrhea:
http://www.flickr.com/photos/tags/logorrhea/
I sort of assumed that someone else would use the Flickr tag logorrhea, but I guess I was wrong.
--update
strangely enough, boing boing posted a link today to Airtight Interactive, a flickr tag search engine/cool tool...that
“lets you surf Flickr's 'tag space'.”
--update the second:
I suppose I'm not the first to think of flickrwhacker, though I did think of it independently. Shite, there goes my Nobel Prize in internet buzzwords.