A vibrator can be like a fire extinguisher; it is rarely needed, but in an emergency can be a real lifesaver. :) Just remember to take the batteries out of the vibe when you leave it setting for a long time, so the batteries don't leak and destroy the motor.

No Exit is the only of those books I have read (I am woefully under-read myself), but it's a real thought-provoker, and definitely one of the classics.