Everybody thinks "dude ranch" came first and was somehow the origin. But whence came the dude in "dude ranch"? Before the dude-ranch dude there was dude as dandy, the dude as an urban aesthete; it was the urbanity of dude that made the dude-ranch dude dude-ish.This is so stupid, but its a smart stupid. Almost Pynchonian, really. Seriously, its a surprisingly complete article, worth reading if only to experience the whopping 160 or so occurrences of the term "Dude" or its derivatives. [via Ipse Dixit - Thanks Dude!]
Update: Unrelated, but interesting: A brief Googling of Pynchon and Dude turned up this article, also by Rosenbaum, about Pynchon and Phone Phreaking.