Late-August is the period of summer when studios dump the baggage they aren’t sure is going to hold water with the movie going public. ‘Classics,’ and I obviously use that term loosely, like “The Avengers” and “The Adventures of Pluto Nash” opened during this time of the year, and goodness knows just this past weekend cinema screens found themselves polluted by the stench of “The Skeleton Key” and “Four Brothers.”

But every now and then, whether planned or not, a good movie sneaks through the web of August stinkers. It’s rare, and it’s usually something coming from an independent source, but it does happen. That’s exactly what’s happening this weekend. Not just one but three decent studio releases (“Red Eye” and “Valiant” being the other two) find their way into multiplexes today, and the most surprisingly entertaining of the bunch might just be Universal Pictures’ R-rated comedy “The 40 Year-Old Virgin” On the surface nothing more than a National Lampoon-style raunch-fest, this (highly) adult sex romp is unexpectedly sweet and full of heart. It’s also laugh-out-loud funny and, quite frankly, the only picture this year where I performed a bona fide spit-take.

Andy Stitzer (Steve Carell) is a perfectly nice guy. Sure, he lives alone and rides a bike to work, and, okay, he’s a tad obsessed with collectables and has a penchant for sitting and playing video games for hours on end, but he’s still a nice person giving with both a smile and helping hand whenever they’re required. But when his coworkers David (Paul Rudd), Jay (Romany Malco) and Cal (Seth Rogen) discover their compatriot is a 40-year-old virgin, the trio takes it upon themselves to make sure their super insecure friend finally lies down and, “gets some.”

Enter Trish (Katherine Keener), an utterly charming sexy single mother of three who just so happens to own a store directly across the way from Andy’s Circuit City-like establishment. The duo hit it off almost from the start, the combination of this woman’s gentle charms and his coworkers’ insistent prodding causing Andy to open up his heart for what may be the very first time. But his insecurity about being a virgin won’t go away, and the closer Andy and Trish come to consummating their burgeoning love the more paranoid he becomes.

At almost two hours, “The 40 Year-Old Virgin” is too long by almost a good thirty minutes. There is a stretch between the second and third acts that just seems to go on forever, the feature plodding here and there like a toddler searching desperately for its sea legs. It’s the perfect time to run out and grab a popcorn refill or take a quick potty break, nothing happening during this interminable stretch worth calling home about. Worse, the extreme homophobic ranting during this section; while sometimes embarrassing-to-admit silly; is almost unconscionable, writers Carell and Judd Aptow (making his feature directorial debut) resorting to clichés so heinous the religious right will probably stand up and cheer.

I may lose friends saying this, but, so what? The movie isn’t just funny, it’s pee-your-pants-squint-your-eyes-slap-the-person-in-front-of-you funny, Carell and company unleashing a smorgasbord of riotous moments rivaling any other comedy this year save for the unspeakably raucous monologues to be found in “The Aristocrats.” This movie works, not only because the jokes click, but also because it has the one thing so many other projects like this forget: a heart. I felt for Andy, wanted to see him, not necessarily have sex, but succeed in finding the things he really wants to experience in life. It’s a sublime journey, one that goes far beyond carnal dreams and forges steadfastly in the realm of what really matters, namely friendship, family, happiness and love.

This film wouldn’t exist without Carell. From his work on “The Daily Show with John Stewart” to stealing the limelight from megastars like Jim Carrey (“Bruce Almighty”), Will Farell (“”Anchorman: The Legend of Ron Jeremy”) and Nicole Kidman (“Bewtiched”), this former Second City star fulfills his promise magnificently with his sensational work here. This man is a comic dynamo, doing things with his face, mannerisms and body that just aren’t humanly possible. If he’s not already a star, Carell sure as heck will be after this.

Yet, as good as he is I cannot for one single second imagine this movie working near as well as it does without the remarkable Keener. An astoundingly brilliant character actress for some time now enlivening picture (“Being John Malkovich”) after picture (“Lovely & Amazing”) after picture (“The Interpreter”) with her presence, she’s simply sensational here. Keener brings so much openness, so much heart to her character it’s hard to not get as consumed by her vivacious presence as Andy does. She’s dazzling, funny and charming and acerbic and sad in each and every one of all the right places.

Sure the movie is thin. Of course it crosses the line into obscene tactlessness a time or two (Leslie Mann’s cameo as a drunken bridal shower attendee will keep me from drinking for a good month at least). Yes, I realize some of it is slightly tedious. But, again I say, so what? Aptow keeps things moving briskly (for the most part) and the script is far more intelligent and perceptive that it probably has any right to be. If anything, here’s hoping this “40 Year-Old Virgin” pops his cherry at the box office, embracing audiences with the same pubescent sexually explosive glee it managed to charm me with.

Film Rating: êêê  (out of 4)