motion sensored first arduino project

okay so im attempting to use arduino for a uni project, essentially im making wearable jewellery that reacts to the movement of another person.
im struggling with how to approach this, im quite arduino illiterate but i cant find anyone to outsource to..
if anyone has any ideas or is willing to help it would be greatly appreciated!
thankyou!

If it's wearable you're probably looking at Arduino LiliPad, and if you're reacting to other people I guess you'll need some way to sense them - perhaps an ultrasonic range detector? I don't think it's possible to go any further without some idea of what this thing needs to do.