Director Ken Kwapis, starring Amber Tamblyn, America Ferrera, Blake Lively, Alexis Bledel, Bradley Whitford and Jenna Boyd.

Finding perfect jeans is tricky, with variables such as leg length, pocket positioning and bum-flattery potential to be carefully considered. Just 'cause they look good on your similar sized mate doesn't mean they will suit you. In this film adaptation of Ann Brashares' novel we encounter the unattainable - a pair of jeans that snugly fit four life-long friends with backsides ranging from Kyliesque to XL JLo.

These teenagers are facing their first summer apart in 16 years and are feeling a little worried about not having their lifelines around. The day before the big separation they go shopping and stumble on these miraculous denims. There is more going on here than Lycra and the girls decide that the jeans' dexterity is a fortuitous sign they should embrace.

They plan to use the jeans as insurance that they will keep in touch for the summer. Each girl takes them for a week and then posts them on with a long letter detailing everything that happens to them in what turns out to be a character-forming few months.

We follow the jeans to a Greek island where impossibly shy Lena ('Sin City's Bledel) goes to stay with her grandparents, and manages to come out of her shell (and the jeans!). Onwards to Carmen (Ferrera) who is spending the summer in South Carolina with her divorced dad who she rarely sees, and who she desperately wants more attention from.

Bridget (newcomer Lively) takes the jeans to soccer camp in Mexico where she stalks the cutie coach with scary resolve. However lurking behind her showy confidence is intense sadness and grief over her mum's suicide. Last of the quartet is Tibby (Tamblyn), who is staying at home in Maryland working in the supermarket and making a condescending "suckumentary" about the banality of this life. She learns her lesson when she unwillingly acquires a wise 12-year-old assistant who teaches her empathy, and that everybody is interesting in their own way.

This tearjerker is loaded with emotional manipulation and scoffing cynics may find their heartstrings inadvertently pulled. Yet, director Ken Kwapis (the US version of 'The Office' and 'Malcolm in the Middle') keeps it all on the right sort of sugary, most of the time. Also adding to the watchable value are some fine performances from the girls.

In a summer of inane, explosive blokebusters, this is one for the teenage girls. Even if you fall well beyond the target market and your heart is hard you might just enjoy it too.

Mary McCarthy