This week at the movies, we've got rock 'n' roll ribaldry (Get Him to the Greek, starring Russell Brand and Jonah Hill); DNA disturbances (Splice, starring Adrien Brody and Sarah Polley); a canine caper (Marmaduke, starring Owen Wilson and William H. Macy); and espionage entanglements (Killers, starring Katherine Heigl and Ashton Kutcher). What do the critics have to say? It might seem like fun to hang with your favorite rock star -- unless you actually have to do it. The critics say Get Him to the Greek takes this inspired premise and wrings plenty of terrific gags from it, making...