Sharon Stone has signed up Hollywood’s top designers for an ambitious new charity project aimed at giving poor teenage girls gowns for their prom nights.

The actress and her sister Kelly have founded the Class of Hope Prom 2007 initiative, aimed at recycling outfits worn to the Oscars and other glitzy big nights.

She says, “We started realizing that kids weren’t going to their proms because they simply didn’t have prom dresses and they could afford them.

“It’s a big ...