This hat was the star of the inauguration ceremony, possibly upstaging even the President:
Theories abounded as to what, if anything, the hat signified and why Justice Scalia might have been sporting it. According to The Atlantic (also the source of these pictures), theories ranged from Olympic beret to Renaissance-era painter's chapeau to Vatican palace guard's hat. To me it looked like a Jiffy Pop in formal wear and I kept expecting it to rise dramatically as soon as Scalia heard something he really didn't like. But maybe it was too cold.
It turns out that the hat is a replica of the one worn by Sir (and/or St.) Thomas More (born 1478, beheaded 1535, canonized 1935), the guy who refused to approve Henry VIII's divorce. (See "beheaded 1535," supra.) It was a gift from the St. Thomas More Society of Richmond, Virginia, so at least Scalia didn't go pick it out himself. The choice may symbolize, as some speculated, a stubborn resistance to authority, a determined conservatism, or allegiance to the Pope; or it could mean his head was cold and that thing was hanging next to the door. We may never know.