Alarm That Stops You From Nodding Off at the Wheel
I sure could use the Nap Alarm from Japanese company Takanoha, following my grotesquely large meals as I have a tendency to hit lunch-time coma while at work. When you start to nod off the alarm vibrates behind your ear to jolt you to awareness. Costs $12 and is available here.
More info here.
Japanese Nap Alarm [i4U]