RuggedCircuits:
The most common method to speed up relay turn-off (AFAIK) is the zener diode.
Sure you don't mean a Schottky? I've never heard of a zener being used for such an application (I'm always willing to learn), but I have seen fast Schottky diodes being recommended for kickback protection for parts like the L298 (vs regular rectifiers), because of their switching speed...?