Going to a Judd Apatow movie is like dropping into a neighborhood bar. There's Judd himself, mixing the drinks. And Bill Hader talking back to the TV. And Paul Rudd and Seth Rogen banging away on the foosball machine. And chubby Jonah Hill over in the corner, hittin' on chicks. It feels just like home.

Rogen is sitting this one out, but everybody else is on hand for Apatow's latest production, "Forgetting Sarah Marshall." Also aboard this time are one of his many writing partners, Nicholas Stoller, who directed the picture, and his old "Freaks and Geeks" pal Jason Segel, who wrote it and stars in it. Also, very happily, there's Russell Brand, an English comic most Americans have probably never heard of, but who is the most compelling reason to see the movie.

The story has an Etch-A-Sketch simplicity. Peter Bretter (Segel) is a frustrated composer who makes his living scoring a TV series called "Crime Scene: Scene of the Crime." (We're shown several excerpts from this show, and since Segel actually worked for a bit on "CSI: Crime Scene Investigation," the snippets have a knowing snap to them. Contemplating one particular atrocity-of-the-week, the show's male lead, drolly played by Billy Baldwin, says, "I don't think she's goin' back to the pageant ... without a face.")

"Crime Scene"'s female star, Sarah Marshall (Kristen Bell), is also Peter's girlfriend — until she surprises him as he's coming out of the shower one day with the news that she's dumping him. "We've been growing apart," she says, sadly. "Who's the dude?" he asks, not fooled for a second. Thus sandbagged, Peter inadvertently drops his towel, treating us to a burst of full-frontal nudity, in which state he plays out the rest of the scene — a first even for an Apatow movie.

Now heartbroken, Peter seeks counsel from his acidulous brother, Brian (Hader), who recommends some simple, no-strings sex. Peter embarks on a series of one-night stands that, while fairly hilarious, are no help. Finally, he decides to just get out of L.A. and head for Hawaii. However, no sooner does he arrive at his Oahu hotel (the whole movie is a budget-slimming advert for the Turtle Bay Resort) than he runs into Sarah, who's there with her new boyfriend, an English rock star named Aldous Snow (Brand). Aldous, who fronts a band called Infant Sorrow, has an alarmingly arched upper lip that forms a perpetual sneer. He's too thoroughly self-absorbed to be offensive, though — he's barely aware that other people exist, except as grateful recipients of his legendary sexual favors. (These can be a mixed blessing, actually. As he says to the appalled Sarah at one point, "I've not told you I have genital herpes, because it's not inflamed at the moment.")

Trying to avoid Sarah and her intimidating new squeeze, Peter heads for the beach to attempt surfing. There he encounters the resort instructor, a perma-baked head case named Chuck (Paul Rudd) — or "Kaunu," the Hawaiian name he's adopted. (Peter asks what Kaunu means. "It means Chuck," says Chuck.) At dinner, securing a pathetic table-for-one in the hotel restaurant, which is thronged with loving couples, Peter makes the acquaintance of a wise-cracking waiter named Matthew (Jonah Hill), an aspiring rock star himself. (Later, when the groveling Matthew asks for Aldous' opinion of a demo he's slipped him, Brand delivers the movie's funniest line with tossed-off perfection.)

Peter is finally pulled out of his downward misery spiral by a beautiful hotel receptionist named Rachel (Mila Kunis), who sets him up in a $6000-a-night suite that happens to be going unused (sure) and then guides him out onto the local party circuit. Love soon blooms. But then Sarah realizes that Aldous — who'll have it off with any woman who even slows down in his vicinity — is definitely Mr. Wrong, and she comes sniffling back to Peter. What now?

That's a rhetorical question, of course. As in most Apatow movies, it's not what's going to happen that concerns us, but how, exactly — and how hysterically — it's going to play out. The picture is very funny in many parts, and it's structured with Apatow's trademark conflation of boundary-nudging raunch (when an S&M-inclined bedmate asks Peter if he'd like to gag her, he replies with a dismayed "Kind of ...") and boldly old-fashioned romantic innocence (Peter is repulsed by casual sex; he wants a relationship). It's Segel's script, of course (Apatow's only one of the producers), but it has the Apatow sensibility — a little sweeter this time around, and not nearly as scabrous as in, say, "Superbad."

Part of this lighter touch is attributable to Segel the actor, who, despite his fearless penchant for the full Monty, is essentially a soulful sad sack. His subtle appeal is not entirely a good thing, however. He's a big, doughy guy, and his hangdog presence is a little too soggy to really carry the picture all the way through. We miss the sort of sneaky comic subversion that Seth Rogen might have brought to the film. Segel always seems to want a hug. Rogen always looks like he'd rather have a beer.

The movie would have benefited from a lot more of Russell Brand, whose surreal egocentricity and vast reserves of disdain light up every scene he's in. The man wields a great line like a whip. Regaling Peter with a story about a disastrous vacation trip with an unsuitable sex bunny, he says, "It was like going on holiday ... not with Hitler maybe — but Goebbels, yeah." Yeah.

Head here for Kurt Loder's review of "Anamorph."

Check out everything we've got on "Forgetting Sarah Marshall."

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