(this is based off LED throwies from grafitti research lab)
A pair of scissors
A 3 volt lithium battery (CR2032)
Electrical (or other) tape
About 1 inch plastic piece
Step 1: Step One
Positive is the longer one and negative the shorter one.
What is seen on the image should happen.
Step 2: Step Two
It will create a division, so, pressing on the two pins should make the LED light up.
Step 3: Final Step
You just made a quick emergency LED Switchie!