Jon Favreau and Vince Vaughn reprise their Mutt-and-Jeff act from "Swingers," but this time in a context uncertainly derived from Martin Scorsese's "Mean Streets." A nasty Los Angeles crime boss (Peter Falk) sends the two men-amateurs as criminals-to New York to do a job. The heavyset Favreau is morose and fearful and just wants to come home in one piece; Vaughn, boastful, unreliable, and stupid, has the time of his life. Favreau, who wrote and directed, veers back and forth between comedy and a more serious tone, and the movie winds up suspended in the air. The two actors try to pull the entire story out of their friendship with each other, but the psychological underpinnings are missing: we never really understand what holds this odd couple together. With Sean (Puffy) Combs, viciously incisive as a downtown Manhattan gangster, and Famke Janssen in a vaguely written part as a lap dancer.