After gracing the cover of Runway Magazine's Summer 2010 Issue, Stephanie Pratt attended the issue's release party in Hollywood to celebrate. "The Hills" star-turned-cover girl posed solo on the red carpet in a smokin' hot strappy black dress before joining equally foxy costar Lo Bosworth (glad to see these two finally stopped fighting over J. Lo).
+ Both Hillzies opted for frocks with eye-catching necklines, but who pulled off this sultry look better? Sound off in the comments!