I swapped Caps Lock with [back]delete (aka Backspace on Windows). My logic is that reaching for delete to fix mistakes is far more common than Caps Locking and also when I'm in various programs where I'm deleting elements. I don't have to reach my left hand far to the right or take my hand off the mouse. Just a quick pinkie move from Home Row and I'm good to go. It took about 4 days to adjust. Also, backspace/delete is moving the cursor to the left, not to the right, so why am I hitting a key that's to the right of center?