I was reminded of the Protest Warrior organization by comment to the SlutWalk article on ROK.
Protest Warrior was very cool. They went to anti-war rallies and held signs that seemed to agree with the anti-war protesters, until their signs were read more clearly.
A commenter pointed out that similar signs might be funny at the slutwalks.
All the sign ideas I could come up with would just be anti-slut, not subtlety so.
A suggestion from another ROK commenter: "Who ate all the hot chicks?"
Does anyone have a better suggestion?