Rock stars are notorious for trashing hotels, but not Queens of the Stone Age front man Josh Homme, who started a rogue beautification movement, Secret Wall Tattoos ( In undisclosed rooms, artists are leaving works in unexpected places: an abstract sketch on the wall behind a mirror, a chalk drawing on the floor under a bed ( this is not sanctioned by T+L). Intrigued by the art form's naughtiness and ingenuity, fans as far away as Australia are emulating Homme. —VICTORIA DE SILVERIO