This is completely nonsubstantive, but I note that the Court's majority opinion in Boumediene cites a draft article up on SSRN:

See Halliday & White, The Suspension Clause: English Text, Imperial Contexts, and American Implications, 94 Va. L. Rev. (forthcoming 2008) (hereinafter Halliday & White) (manuscript, at 11, online at http://papers.ssrn.com/sol3 /papers.cfm?abstract_id=1008252 (all Internet materials as visited June 9, 2008, and available in Clerk of Court's case file) (noting that "conceptually the writ arose from a theory of power rather than a theory of liberty")).

As far as I know, that's the first Supreme Court citation to a forthcoming article that is on SSRN. I would guess that the citation will be changed to the final version by the time the Boumediene case is compiled into the U.S. Reports, so in the end the Court's opinion will cite an article as published that wasn't when the opinion was handed down. Kinda cool.