Justification: Because You Can't Write Kidlit Without Words
It says of itself that it is, "Like Flickr, but without the photos", but a closer approximation to the Wordie site might have to be Wikipedia.
Wordie lets you make lists of words -- practical lists, words you love, words you hate, whatever. See who else has listed the same words, add citations and comments, and discuss.People who've left the most words are called the Wordiest Wordies. For me, though, the comments are the true draw. Check out what people wrote when someone submitted the word oroboros, for example.
Thanks to Eric Berlin for the link.