Rising above its billing as "formerly New Zealand's fourth most popular guitar-based digi-bongo a cappella-rap-funk-comedy folk duo," the Flight of the Conchords continues its stateside comic assault. In addition to the hit HBO series, a 2007 Grammy win and an upcoming album on Sub Pop, the duo of Bret McKenzie and Jemaine Clement is now adding "arena headliner" to the resume.