This is a project I did for my wearable technology class. It is a BlinkM with a mercury switch sewn to a glove. When your hand is down the device is off but when you have a question you simply raise your hand and the mercury makes the electrical connection activating the light making you stand out as though your question can't be missed! A wonderful blend of digital and analogue tech.
Print off the box
I used a ping pong ball as the dome defuser
wire it up with a 3v lithium battery
sew it to the glove
ask lots of questions!