The small lights can easily be placed on your jacket or hat. They will help people see you when you cycle while it is dark outside.
Step 1: The parts
1, A small metal binder clip
2. masking tape (other types of tape would work but I find masking tape easy to use)
Less common items:
1. LEDs (the yellow and red were my choice) A package of 20 assorted LEDs at Radioshack goes for about $3.00. But if you are serious about lowering your cost buy the LEDs online. There are many online suppliers. The Electronic Goldmine site (interesting site I plan to use soon) had various packages of LEDs. You want T1 type and I think 5mm size is good. I believe the red, amber and green are the cheapest.
2. Small batteries. These battery are used for travel clocks and lately they show up in those musical greeting cards. I bought an off-brand pack of 24 for about $3.00.
So depend on the quantities purchased you should be able to make the lights for less than a $1 each.
Note the positive lead of the LED is slightly longer than the negative lead. The positive and negative leads must be connected correctly for the LED to light.