Huh. Flickr actually uses keywords on a global database scale,
rather than just for each particular user:
Flickr "tags" are user-created keywords that describe their photos. If two or more users hit on (or agree upon) the same tags, all photos with a common tag are grouped together. That's pretty cool -- a kind of Wiki-style serindipitous metadata thing.
It is. My caveat: Well, dang. If I'd known that, I'd have made some effort to label my photos
with tags that actually matched existing ones in the system, instead of just which streets I was walking on that day
. Or marked them all with the "Ottawa"
tag, at least. And I'm lazy enough I doubt I'll go back to fix older entries.
It's a fantastically spiffy feature, but it kinda needs to be promoted a bit more, I think; the greater number of users take advantage of it, the more useful any given tag will be.