It's only June, but our Chagrin Falls (Ohio) office is already gearing up for the holiday season. Part of that gearing up is clearing room for all the new t-shirts we have up our sleeves. To free some shelf space, we've put certain t-shirts on sale for $12, such as "Beethoven: The Original Deaf Jam" and "Kinetic Energy: Pass It On."

To see all the $12 shirts, visit the Outlet section of the mental_floss store. Once they're gone, they're gone for good. So order now or you'll have to make your own "Karl Marx: Sharing Is Caring" shirt.