Ashley Greene Preps for Prom

Ashley Greene is prepping for prom... even though she's not exactly going.

The third time's a charm! The Twilight sweetheart has returned for the third time as the official spokeswoman for DonateMyDress.org, an organization that collects gently worn dresses to help girls in need enjoy their big day.

Greene recently told People Magazine, "In high school, I had to work several jobs to save enough to buy a prom dress... It was so worth it: I had a blast at prom! Every girl should have the chance to have that experience."

The actress will be donating her gown that she wore at the Chrysalis Butterfly Gala (pictured above) too. What a doll! As the date of prom inches closer, check out what you can do to make the prom experience more green.