Holly Madison: Nude for PETA
Granted, it doesn't take a lot to get Holly Madison nude.
But she isn't doing it for a hot tub party or to fulfill the wishes of Hugh Hefner in this picture.
Instead, one of the three Girls Next Door - and Hef's main squeeze - is participating in an ad campaign for PETA. She wants to save the world, one animal (and layer of clothing) at a time: