I know that Dr Nakamatsu (creator of CDs and moon shoes and many other gizmos) only sleeps 4 hours a day as he does not want to lose his concentration power to think of new inventions :\
Then again he goes to extremes and near-drowns himself to death because he feels when he's running out of oxygen he can suddenly think of an invention in the instance
Who knows, maybe if we sleep less we'll all be awesome thinkers and own a golden toilet like Nakamatsu
Anywho, personally I sleep all I want on holidays/weekends to make up for my lack on school days