From a bit more Googling, this page claims it was coined in 2002 by "Mooncalf", in this blog post (which then, presumably, spawned or at least inspired the Googlebombing).
Another site claims it was coined on December 18th, 2001 by the same person, but for whatever it's worth, there's no blog post by (her?) on that date.
Another site claims it was coined on December 18th, 2001 by the same person, but for whatever it's worth, there's no blog post by (her?) on that date.