Hide In Plain Sight (DnD Hide Skill Use)
From D&D Wiki
You can use the Hide skill even while being observed. As long as you are within 10 feet of some sort of shadow, you can hide yourself from view in the open without anything to actually hide behind. You cannot, however, hide in your own shadow. You must take a -40 penalty to your hide check to do this. If you take a -80 penalty to your hide check you may use the Hide skill even while being observed regardless of your environment.