After upgrading my gaming rig and removing most of my hard drives, I decided to shell them and connect them via USB. As my collection of hard drives grew, I ended up building a custom expandable rack out of K'nex to hold them all.
I figured it might not be a bad idea to add a cooling unit to it as well, to help disperse the heat so I designed a detachable cooler, also out of K'nex that goes on the front, housing (3x) 120mm case fans. I recycled the control board from an old, dead hard drive shell to power the fans through its molex plug. I even added a power switch to the top to control the fans! All in all I was really happy with how this turned out.
I don't use it any more however, and now have a dedicated data server box with a raid card that houses all my hard drives instead. Much more portable and logical than my initial approach.