4 of 6 added 163 characters in body

SmileBASIC, 36 23 bytes

XON MIC
WAIT 30XOFF MIC

Blinks the microphone status light. (video coming soon)

21 bytes:

ACLS
WAIT 30XSCREEN 1

This blinks the 3D indicator light, but I'm not sure if it counts as being "physically located on your keyboard"