"Google Crashers" must have been the high-concept pitch for "The Internship," which reteams "Wedding Crashers" stars Vince Vaughn and Owen Wilson for a round of markedly less ribald shenanigans, this time as two washed-up Willy Lomans trying to reinvent themselves as tech-sector whiz kids. "The Social Network" it isn't -- nor does it try to be -- but this big-hearted underdog comedy from director Shawn Levy is, much like its two leads, exceedingly affable and good-natured despite being undeniably long in the tooth. Low-key pic faces its own generation-gap standoff at the summer box office, where it opens just five days ahead of the more buzzed-about hipster doomsday farce "This Is the End" -- a reminder that much has changed in American screen comedy in the eight years since "Crashers" racked up a $200-million-plus domestic total.

Fittingly for a movie stuffed with '80s pop-culture references (including Vaughn's frequent invocations of "Flashdance" as an inspirational touchstone), "The Internship" often feels like a time-travel or body-switching comedy a la "Big" and "Peggy Sue Got Married," but where nothing supernatural is responsible for stranding Los Angeles watch salesmen Billy (Vaughn) and Nick (Wilson) in a world they no longer recognize.

Newly downsized (and, in Billy's case, kicked to the curb by his fed-up girlfriend), the two best buds flounder for a while, with Nick taking a soul-crushing job selling mattresses for his sister's lecherous boyfriend (an uncredited Will Ferrell). Then Billy hits upon the idea that they should work for Google, no matter their collective lack of technological know-how and the fact that Google isn't actually hiring. But the search-engine giant is looking for candidates for a highly competitive summer internship program that guarantees a select number of staff positions to its highest achievers. So the boys enroll themselves in an online university (to qualify as students) and audition for the Google search committee -- a very funny scene, staged as a videoconference, that makes a fine showcase for both actors' considerable improvisational gifts.

When they are improbably accepted into the program, it's off to Silicon Valley and Google's corporate HQ, depicted as the happiest workplace on earth, complete with driverless cars, beach volleyball court, adult-sized tunnel slide and gratis employee cafeteria. (In the annals of product-placement cinema, no corporate giant has been so fully integrated into a movie's very conception since FedEx and "Cast Away.") There, Billy and Nick aren't merely square pegs in round holes; they're like over-the-hill Gullivers stranded in a high-tech Lilliputia, the gangly Billy towering over the uniformly bookish, slope-shouldered interns, who in turn regard him and Nick as mental midgets recruited for diversity's sake -- none more so than Alpha-male a-hole Graham (Max Minghella). Used to being picked first for high-school sports, these jocks-out-of-water now find themselves in the reject pile, forced to work with a ragtag bunch of similar also-rans in a series of competitive team challenges designed to weed out the best and the brightest from the sea of "Nooglers."

It's fairly easy to see that, in pic's grand design, Billy and Nick's apparent liabilities will turn out to be assets, their real-world life experience and people skills complementing the book smarts of their socially regressed colleagues. But "The Internship" gets surprising mileage out of the premise, thanks to the infectious chemistry of Wilson and Vaughn and the gallery of equally fine comic performers who back them up, including a scene-stealing Aasif Mandvi (as the internship program's whip-cracking leader), the lovely Rose Byrne (as the lovelorn staffer who catches the eye of longtime bachelor Nick) and newcomer Josh Brener as the barely pubescent manager assigned to Nick and Billy's team.

Indeed, given how much "The Internship" has going for it, it's doubly disappointing when the movie sells itself short with dumb, unconvincing gags (including one that turns on pop-culture junkies Billy and Nick never having heard of "X-Men") and overextended setpieces, chiefly a long second-act foray into a San Francisco strip club that seems to have parachuted in from a different movie (and which may offend some of this otherwise family-friendly pic's potential audience). Few comedies can sustain a full two hours of screen time without at least partly overstaying their welcome -- Levy's 2010 "Date Night" clocked in at a lean 88 minutes -- and there is almost surely a tighter, sharper, 100-minute version of "The Internship" lurking somewhere in this current version's 119-minute frame.

Still, the pic's unwavering charm keeps it afloat. Levy, who cut his directorial teeth on Disney TV series before going on to steward the lucrative "Night at the Museum" and "Cheaper by the Dozen" franchises, doesn't seem to have a cynical or mean-spirited bone in his filmmaking body, and there's something finally disarming about "The Internship's" boundless optimism, its belief in the possibility of starting over at 40, and its vision of Google as something like the world's biggest mom-and-pop business. Who know's if that's really the case -- but hey, it's only a movie.

Production designer Tom Meyer impressively re-creates Google's Mountain View, Calif., campus on the grounds of Georgia Tech, where it has been lensed in brightly lit and colored digital widescreen by Jonathan Brown.