If you'd like to save money on gas and ride around on a bicycle instead of driving to work everyday, then this shirt tutorial might make you feel a bit more safe. Although biking saves money, all the traffic and people in a rush can be dangerous and this sweater lets drivers know which direction you are going
I have to admit, I moved to a small city and the traffic conditions tend to be a bit congested and on the hazardous side. Which means, I really don't feel like going out on a bike into a bunch of traffic. The tutorial on Instructables teaches you how to put some LED lights into your sweater, that also includes a brief video.
The way to turn on the signals are the buttons which are mounted on the inside of the wrists. You have to hit the button to turn them on as well as off and she suggests turning them both on for any night riding you might do.