I planned to build a NAS out of a old core-2 tower. So I bought three drives to throw at it. After I mounted two of them, I realised that I neither have a slot for the third drive nor for the OS disc. I mounted the third data drive in the floppy drive slot. This left me with no place to mount the OS disc (and two spare 5 1/4 inch slots).
Since the OS disc is old and therefore a bit noisy, I thought it would be great to mount it in a way that kept it silent. With some rubber bands and cable ties the hard drive was silently mounted in a one of the large slots.