If, like me, you have an external hard disk, you may have noticed that sometimes the disk will shut off to save power once it hasn't been used for a while. Usually, this is fine. But if you store games or music on the drive, you may notice that some or all of the applications on your computer will completely lock up while waiting for the drive to power back up. If this happens while you're playing a very lag-sensitive game like World of Warcraft or Guild Wars, you'll be understandably upset.
My little external hard disk likes to spin down, so I wrote a little program called Spinner that (in theory) stops it from doing so. What it does is let you pick a drive and set a number of seconds, and every X seconds Spinner will pick a random directory on that drive and read some data from a file in that directory. Since the directory and file are random, Windows will have no choice but to spin the drive up and read the file. Since Spinner does this in the background and does it frequently, the drive should never spin down.
Source code included. Requires .NET Framework 2.0.
http://luminance.org/f/Spinner.zip