Here’s a crafty solution to noisy hard disks: suspend it with elastic! Jason @ HACKS tipped us off to this silencing technique. From Silent PC Review:

As the pictures show, the drive is essentially suspended on the stretched elastic. The resilience of the elastic stops all vibrations from passing from the drive to the case — or vice versa, for that matter. The drive cage was rigged it up with two Barracuda drives (20G & 40G) and installed with a couple of machine screws at the bottom of my main PC with a decoupled low power 80mm fan in front of it (at the front panel intake hole).

Jason adds:

Keep in mind that you’ll loose some of the conductive cooling that you get when the drive is mounted to the case, so it’d be smart to do this in cases where there is decent airflow or find a way to attach some sort of heatsink to the bungeed drive.