The pants of the title are jeans that the girls half-jokingly believe have magical powers, in part because they fit each one of them, despite their varying sizes. As the girls part for the summer, they vow to share the pants week by week, via the mail.

Sure, it's a corny narrative device, but it provides a tangible link between four different stories. "Sisterhood," in other words, is an anthology of four tales involving teenage girls. That's a good thing, because none of the stories could stand the way of a full-fledged feature, yet, they're appealing in 20-minute increments.

Each girl goes through an affecting experience, and yet the link of friendship remains a strong motif. Tibby (Amber Tamblyn of "Joan of Arcadia") is the most cynical of the four, and is particularly gloomy because she's to stay home all summer and work at a discount department store of the Wal-Mart variety.

To make life tolerable, she begins work on a journal-like video she calls a "suckumentary," about the supposed losers around her. Her attitude changes when one of those losers — a pesky 12-year-old neighbor (Jenna Boyd of "The Missing") — becomes an unexpected friend.

Carmen (America Ferrera, "Real Women Have Curves") is excited to be spending the summer with her seldom-seen, estranged father ("The West Wing's" Bradley Whitford). But once she arrives, she's sad to find he's preoccupied with the new woman in his life, and her children.

The cocky and flirtatious Bridget (relative newcomer Blake Lively, ), an expert soccer player, heads for Mexico to a high-end soccer camp, with the overly obvious goal of romancing one of the handsome young coaches.

But shy Lena (Alexis Bledel, "Sin City") wins the prize for best vacation — she spends the summer living with old-country relatives on a sun-drenched Greek island. And she falls in love.