Andrew O'Hehir of Salon has a good piece on “Chinatown” and the Polanski problem. First really good line:

Towne's original script, he tells us in an accompanying featurette [of the DVD], included no scene actually set in L.A.'s Chinatown; it was Polanski who insisted that the movie's racially tinged guiding metaphor had to be made explicit. After Nicholson's Jake and Dunaway's Evelyn Mulwray finally go to bed (for the one and only time), he tells her that he used to be a cop in Chinatown, where “you never really know what's going on.” He once tried to protect a woman there, and only ended up making sure she got hurt. “Dead?” Evelyn asks him, and then the phone rings. It's the end of the movie calling.

Second really good line:

I am certainly not speaking out in defense of Roman Polanski, who apparently did something that was both heinous and illegal, and should long ago have faced the consequences. I guess I'm saying that it's hypothetically possible to learn something from a movie, and totally impossible to learn anything from the sordid private lives of celebrities.

Entire thing.