[{SRD}Assassin[1]], 8th level (SU) ability
Hide in Plain Sight (Su): (Su): At 8th level, an assassin can use the Hide skill even while being observed. As long as he is within 10 feet of some sort of shadow, an assassin can hide himself from view in the open without having anything to actually hide behind.
He cannot, however, hide in his own shadow.