Can I change the Caps Lock key to Control and still keep the on/off nature of Caps Lock? I've checked into using xmodmap and seem to have hit a dead end. Many people want to swap them, but they also want to swap the way they work. I'd rather keep my new Control key as an on/off switch for Control.
There's no low-level support for a Ctrl Lock in either Linux or Xorg outside of bugs, so you'll either need software that will feed the Ctrl press back into some input buffer in order to simulate a lock, or you'll need a keyboard that supports it directly.