Here is the ghost
It has the latest arduino and Ladyada motorshield
Ther are three pair of LED - green and two red.
Red ones are closer to each other and lower - when you walk close, his eyes follow you.
There are two stepper motors supposed to lift his arms, but they do not work very good. The morots are from CD drive, and are not powerful enough (they try hard though), or may be motor sheild does not yield enough power?
There is vibrating motor from toy frontloader. With 12V it vibrates way to fast - you cannot really see it on a video, you can just hear the noise, but when you come close, and it suddenly start vibrating - that's spooky :)
The ghost, just like a bat, relies on ultrasonic distance sensor :)
Here are some pictures: