Sensing movement

The appearance of independent, random movement is one direction i want to take my monster. the idea being that movement will be stimulated by other devices and responded with movement from movement. the light sensor circuit achieves a motion sensor element, but how to obtain random, or differentiated movement was still a question i had in mind. I created a circuit, from make magazine site, http://www.make-digital.com/make/vol10/?pg=66&search=555&liid=eb284a0105%20target=&u1=texterity&cookies=1

I was able to use a 555 timer to make a LED blink 5 times a second. I am hoping to use this circuit in some way to differentiate motor movement and/or affect LEDs that will be attached to the monster. After a short discussion with guest crit Jean-Pierre Gauthier, he had suggested mercury switches, or tilt switches to switch the polarity of the motor.

The act of a movement from the monster will either activate another motor, device or reverse the action it is currently in. A more random movement may occur as a result of movement that is activated through movement from the audience or other devices.