Jason Reitman's delightful comedy Juno is about a 16-year-old girl who discovers she is pregnant two months and four days after she loses her virginity to the local high-school geek. The film has banked an astonishing $100 million in just eight weeks, and only a stone-hearted curmudgeon would begrudge it a single cent. It is a light-fingered Farrelly Brothers-style fable with folk songs to match. Ellen Page is the hapless title heroine, and she is a quirky and precocious joy. She sulks and hides her natural beauty under a red hoodie, showing a weary horror at the slings and arrows of unreliable parents and outrageous bad luck.

There hasn't been a mordantly funny adolescent quite like her since Thora Birch in Terry Zwigoff's cult comedy Ghost World (2001). The film begins with Juno staring dazed and confused at her third positive pregnancy-test reading. Her father (J.K. Simmons) and step-mother (Allison Janney) are duly stunned, and then horrified when Juno decides to have the baby and give it to a childless yuppie couple who have placed an advert in the local gazette. This spontaneous act of generosity gives rise to a surprisingly affecting rites-of-passage movie. I found myself wiping away a tear.

Juno is so disarmingly relaxed and laissez-faire about the deal that the grateful couple, and their expensive lawyer, are forever wrong-footed by her cheek. Jennifer Garner is the nail-scrapingly neurotic and desperate would-be mother. The humour turns into an uneasy drama when her husband (Jason Bateman) starts falling for Juno's charms. The attraction is mutual. He is a closet rock musician who hasn't grown up. Juno thinks she is an adult. Comedy as sharp and bitter-sweet as this is all too rare. One to cherish.

12A, 91 mins

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