A big thank-you indeed for this acutely hilarious film version of Christopher Buckley’s novel about a certain Dr. Spin and how he learned to stop worrying and love the butt. Directed and written by first-timer Jason Reitman, the generously gifted son of Ghostbusters impresario Ivan, Thank You for Smoking mines comic gold from a topic that’s no laughing matter. Aaron Eckhart is a fierce and funny dynamo as Nick Naylor, a tobacco lobbyist who enjoys comparing notes with Polly (marvelous Maria Bello) — she sells alcohol — and Bobby Jay (deadpan David Koechner) — he hustles guns. These Merchants of Death (the MOD Squad) verbally skewer the liberal do-gooders who’d like to hoist them on their own lethal petards. Nick is the first among equals, despite the disdain of his ex-wife (Kim Dickens), who hates him inculcating their son (Cameron Bright) in his unholy crusade. Nick should be smart enough to dodge hottie reporter Heather Holloway (Katie Holmes), but his dick leads him astray when she strips (note to prudes: Holmes shot the film before she became the pregnant future bride of Tom Cruise). The movie reaches its peak when a tobacco tycoon (Robert Duvall), besieged by attacks from an anti-smoking senator (William H. Macy), sends Nick to Los Angeles to get Hollywood on the smoking bandwagon. Superagent Jeff Megall (Rob Lowe is a hoot) tells Nick that for the right price — roughly half the film’s budget — he can have Brad Pitt and Catherine Zeta-Jones light up after sex even though they’re shooting a space epic. Another plus: Ethics never get in the way of the jokes. Both sides of the political fence will feel royally skewered. All that’s lacking is a warning from the Surgeon General: This film will make you laugh till it hurts.