AGE: 29. PROVENANCE: Born in Stockholm, raised in Toronto.  YOU MIGHT REMEMBER HER AS. . . the breezy young beauty who stole Lisa Kudrow's thunder in the 2005 HBO series The Comeback. And this past summer, she was the nut-job bride who inspired buyer's remorse in Ben Stiller in The Heartbreak Kid. BREAKING HEARTS AGAIN AS. . . Katherine Heigl's kid sister in the new movie 27 Dresses, in which Heigl, as a perennial bridesmaid, helps plan Akerman's character's wedding, while pining for the groom (Ed Burns). AND SOON BUSTING OUT OF THE ROM-COM MOLD WITH. . . a starring role in Watchmen, the next C.G.l.-action extravaganza from director Zack (300) Snyder. FRONTS A BAND IN HER SPARE TIME CALLED. . . the Petalstones, anchored by her drummer husband, Roberto Zincone. "It's a bit like Evanescence mixed with Linkin Park," Akerman says. "It's pretty heavy stuff."