I think, maybe, when one has 2.5 times as many photographs on Flickr as does the Library of Congress, it’s time to approach one’s photography with a little more discernment.
Even if you’re not into photography, there are some really fantastic historical images in the LOC’s stream. And if you’re cool enough to have a Flickr account, you can actually contribute tags to the photos to help in classifying them. Flickr calls it “The Commons.” It’s actually kind of fun trying to think up tags that don’t already appear with the image.