Stiffy
Many moons ago, when 'mass storage' meant a 5.25" floppy disk holding 720kB of data or whatever, you had two main forms of data storage. The aforesaid floppy, or one of those new fangled expensive 'hard disks'.

So when the 3.5" disk came in, it was kind of rigid, and half way between floppy and hard...so it was suggested that it should be referred to as a stiffy.

This stuck at my place of employment, and for years afterwards the phrase "Have you got a stiffy?" could be heard frequently when asking to borrow a data storage medium.
( K2k6 has a proper job these days, Wed 3 Dec 2008, 18:53, Reply)