I used to think that I was the only person who did this, but as my horizons have widened slightly I've realized I'm just one in the crowd. But it's still a minority group to be sure, so I'm doing my part to evangelize.
The standard keyboard layout puts the Caps Lock key to the left of the A key and it puts the right Ctrl key in the bottom left. This means Caps Lock is basically on the home row while Ctrl is behind and almost under your hand. This seems backwards to me as I never use Caps Lock, but I use Control about 10,000 times a day (Ctrl+S, Ctrl+click in Firefox, Ctrl+C, Ctrl+V, Ctrl+Z, etc).
So, as I briefly mentioned in a post about Keyboards almost a full year ago, it would seem to make sense to swap the Caps Lock and Control keys so that the key you use frequently is on the home row.
When I first did this a very long time ago I muddled around deep in the Windows registry and came up with a .reg file you could use. But I recently stumbled on a much easier way: just use SharpKeys. If you use an operation system other than Windows, hit up Google and you'll find tutorials on how to do it for your OS.