In Mac OS X, you can remap the Caps Lock key to any of the modifier keys.

System Preferences > Keyboard > Keyboard Tab > Modifier Keys… button

modifier-keys-dialog

Because when was the last time you actually used Caps Lock?

BONUS FEATURE:

Some early keyboards had the Control key where we’re used to having the Caps Lock key: https://en.wikipedia.org/wiki/Caps_lock#Caps_Lock_versus_Control_key

SOURCE:

Pro tips from Beau Lyddon