This is like the fourth time I've blogged and forgotten to mention that I've added keyboard shortcuts on the practice page for left-handers. They are essentially mirrors of the right-handed shortcuts, plus 6, 7, 8, 9, and 0 for tones.

So now the shortcuts are:
Erase: Z or /
Undo: X or .
Correct: V or M
Phantom: S or L
Next: Space or Enter/Return (numpad return works, too)
Tones: 1-5 or 6-0 (6-0 don't work on numpad without numlock)