I realize on second reading of this that they have specific open positions, 53 of them to be exact, but the way it reads is that anyone should decide what they'll apply in, and just send a letter unsolicited to the appropriate department.
I did see a small college recruiting in such a way, though, which makes sense. And they don't teach enough of my field so maybe I have a chance!
Position: Multiple Positions
Institution: Princeton University
Location: New Jersey
Date posted: 10/22/2007
Princeton University invites applications from junior and senior scholars for positions as tenure-track assistant professor, or tenured associate or full professor in any of its departments in the humanities, social sciences, natural sciences, or engineering.
Princeton University is an equal opportunity employer and complies with applicable EEO and affirmative action regulations. Please submit a cover letter and cv online at http://jobs.princeton.edu.