Vibrator
From Openmoko
Vibrator
This is in reference to the vibrator in the Neo Freerunner, however it is likely identical to the Neo 1973, as best I can tell.
Controlling
The vibrator is controlled through:
/sys/class/leds/neo1973\:vibrator/brightness
When off, it will read 0. Valid ranges appear to be 0-255, with 255 being the fastest.