Comedian Chris Hardwick, 32, and musician Mark Phirman, 30, started pun-loving duo Hard'n Phirm -- think Tenacious D without the classic-rock angst -- back in 1994 at UCLA. Now their geeky dorm-room humor has become a hot online commodity in the form of ''Rodeohead,'' HNP's silly, yet surprisingly listenable bluegrass medley of Radiohead songs. ''It was just one of the billion and a half hacky ideas that you come up with and giggle,'' says Hardwick, former host of TV's ''Singled Out'' and ''Shipmates.'' ''For some reason, we just couldn't stop talking about it.'' Years later, the two strung together their favorite Yorke-y laments in the key of yee haw and watched in amazement as 100,000 people downloaded the tune from hardnphirm.com. Even Phirman's mom -- not previously a Radiohead fan -- hopped on the bandwagon. ''She was at the market the other day singing the lyrics [to ''Amnesiac'''s ''Morning Bell''] and didn't realize what it was,'' he says. ''The woman next to her was like, 'My God! What is that?' She was singing 'Cut the kids in half.'''