"Wow. What on Earth is going on with Joaquin Phoenix?" asked Maureen Ryan in the Chicago Tribune. He made a "surreal" appearance on "The Late Show With David Letterman" Wednesday night, speaking in monosyllables, chewing gum, wearing shades, and mumbling about his new rap career (click here for the video). As the interview ended, Letterman said, "Joaquin, I'm sorry you couldn't be here tonight."

This was "an exercise in squirmingly uncomfortable comic gold," said Craig Newman in the Chicago Sun-Times. Phoenix was on to promote his new movie, "Two Lovers," or his rap career, "or ... well ... who knows, really." All mystified viewers seem concerned about is whether he was high or "just a jerk." And, "what's up with the beard?"

Phoenix's behavior has turned Friday's opening of "Two Lovers" into "a circus nearly as surreal as anything staged by Fellini or Cirque du Soleil," said John Horn in the Los Angeles Times. Phoenix says the film is his "swan song"—he's retiring from acting to devote himself to music. The "unusual declaration" is overshadowing the film itself, "seriously testing the long-standing adage that there's no such thing as bad publicity."