I lost 5 seconds of waiting on my POST by doing this.

Go into your BIOS. Find the section that deals with your IDE/SATA.

For every IDE/SATA port you are not using, set them to "None" instead of "Auto".

Normally when you boot up your BIOS checks each of those ports to see if anything is connected. By doing this you save it precious time and it only checks the bare minimum. (In my case just 1 hard drive).