A surprisingly cleaned up Joaquin Phoenix, who plays an even more surprisingly disturbed Joaquin Phoenix in Casey Affleck's documentary-styled film I'm Still Here, appeared on The Late Show with David Letterman last night, marking his return to the late night talk show for the first time since his "disastrous" appearance in February 2009.

Phoenix explained that he and Affleck had sought out to create a film "that explored celebrity and explored the relationship between the media and the consumers and the celebrities themselves." Appearing on a late night program such as Letterman's was important to both Phoenix and Affleck, though the actor dismissed reports that Letterman was ever in on the joke.

"I thought that you've interviewed many people and that you would know the difference between a character and a real person, but I apologize," he told the host. "I hope I didn't offend you in any way."

Letterman said that he wasn't offended by Phoenix's appearance; on the contrary, "it was like batting practice. Every one of them was a dinger!" At the conclusion of Phoenix's visit, Letterman warned the Oscar-nominated actor that he wants "a million bucks" from the I'm Still Here team to cover the "free publicity and a talent fee."

"It's not my first rodeo," Letterman joked. "I want a little taste myself!"