Juno MacGuff is the kind of teenager we all wish we could have been: quick-witted, frighteningly intelligent beyond her years and comfortable enough in her own skin to resist those incessant high-school pressures to conform, even as her body expands with an unplanned pregnancy.

And "Juno" is the kind of movie all indie comedies wish they could be: light and lovable, perhaps a bit too pleased with the cleverness of its dialogue, but a small charmer nonetheless.

It's also sure to make a star of the appealing Ellen Page, who had already proven she could be a tiny force of nature in the tense but little-seen "Hard Candy". Page was subsequently nominated for an Academy Award for her role.

Page absolutely shines in this second feature from director Jason Reitman, who once again shows a deft touch with tone following his 2006 debut, "Thank You for Smoking". There's a lovely openness to her face, an accessibility to her demeanour, even when she's being smart-alecky and cynical.

It certainly doesn't hurt that stripper-turned-screenwriter Diablo Cody has given her such delightful and disarming turns of phrase at every turn. (And Cody's story is just about as eventful as that of the character she created.)

Juno is almost superhuman in her ability to say just the right funny or poignant thing in any given situation, from telling her inordinately understanding dad and stepmom (J.K. Simmons and Allison Janney) she's pregnant to bickering with her best friend and baby-daddy (the adorably awkward Michael Cera) about the prom.

But these days, she has more important matters that require her attention.

Having gotten knocked up from a one-time boredom romp with Cera's Paulie Bleeker, Juno decides to have the baby and give it up for adoption to wealthy suburbanites Mark and Vanessa Loring (Jason Bateman and Jennifer Garner), who had been trying for years to have a child of their own with no success. In one of the movie's many quirks, she finds the couple while perusing ads in the PennySaver with her loyal sidekick, Leah (Olivia Thirlby, who gets some of the best lines).

Their life couldn't be more different from her own, with their perfect McMansion and precise taste in clothes and furnishings. Vanessa likes the ultrapopular Madison as a girl's name, which tells you everything you need to know about her personality. (Juno, meanwhile, wears vintage T-shirts over her elastic-waistband jeans and talks on a telephone shaped like a hamburger.

But after a few visits to share details about ultrasounds and such, Juno and Mark find they have similar interests in music and movies — and Juno does have extraordinary tastes for someone her age, from the songs of Iggy and the Stooges to the horror flicks of Dario Argento. She might actually be too cool.

The teenage girl reminds this thirtysomething man of his former dreams of rock stardom, which he'd long since abandoned for the safe rigidity of grown-up life. Here's where things get a little creepy — and where "Juno" gets more interesting as it morphs from blithe hipster humour into something more substantive and real.

"Juno," (PG-13) is showing at the Neptune Theatre.