Some guy came up with one of the most ingenious uses of elastic since putting it in clothing. He used bands of elastic to suspend the hard drives in his computer thus reducing the noise made by his hard drives.
Picture courtesy of Jason at HACKS
As its been stated, the one downside to this hack is that you lose the passive cooling that was occurring when the drives were attached to your case. Also, you’ll either have to use up your optical drive bays, buy smaller hard drives, or make a custom drive cage to do this.
However the cost should be minimal as the last I checked elastic was pretty cheap and plentifully available from your favorite department store. This might not be beneficial to you at all unless you are having some serious issues with noise, but remember, you have to have plenty of airflow inside your case if you are going to do this or your drives might go all China syndrome on you.