A romantic comedy is only as irresistible as are its temporarily star-crossed lovers. By this barometer, the enjoyably breezy "Must Love Dogs" boasts quite a pedigree.

Starring the reliably effervescent Diane Lane and John Cusack - the one man every woman between the ages of 25 and 55 can agree is the Perfect Boyfriend - the film is goofy and improbable and as unsurprising as most TV sitcoms. But it's also spritely, well-acted and a great deal of fun, probably the best date movie of the summer.

Contrary to what you might expect, the main characters don't even own dogs. They borrow them on occasion, possibly to increase the movie's Awww factor, which rockets off the charts at every appearance of Mother Teresa, an adorable and suspiciously obedient Newfoundland. But "must love dogs" is a crucial requirement of the online profile of Sarah Nolan (Lane), who has been divorced for eight months and is only tentatively back in the dating world after much nagging by her large Irish family, headed by her widowed father (Christopher Plummer).

In a grand achievement of product placement, Sarah and her dad end up trolling perfectmatch.com for prospective mates. Dad meets lively Dolly (Stockard Channing). After a stereotypical series of horrific encounters with losers, Sarah hooks up with Jake (Cusack), who has the required artistic and noble career of hand-building gorgeous wooden racing sculls, plus a cool name. Jake is recently divorced, broken-hearted, with a tendency to lounge around watching "Dr. Zhivago" and proclaiming his need for a love that transcends time. If this guy actually existed, a dating Web site is the last place he'd need to visit.

Sarah and Jake are perfect for each other, of course, but formula dictates roadblocks. One snag comes in the form of the handsome dad of one of Sarah's students (Dermot Mulroney), for whom Sarah has more than a passing interest. Other hitches occur thanks to Jake himself, who tends to babble incoherently when he's nervous.

The boyish Cusack, who is finally starting to look his age, is more schlumpy here than usual, although he's every bit as appealing at 39 as he was in younger days.

Nothing unexpected happens in "Must Love Dogs"; there's nothing to make you think or reconsider your life. The film's revelations are modest and yet universally appealing. View it as a fat-free but tasty cinematic treat in the middle of the long, hot summer. And you didn't even have to beg for it.