Wow, Refalm, that totally rules! Useful for typing or playing games in the dark, and stylish.
Jack, was that what you wanted?
The resistor thing is quite important.... take the voltage listed for the LED (say 1.5V). Subtract it from your power supply (say 5 V for this example, leaving 3.5 v). Now look at the current listed for the LED, say, 5 mA.
Divide the remaining voltage by the current and you get the resistor size you need, for this example 3.5 V/5 mA = 3.5V/0.005A =700 OHM I go to radio shack and have a choice between a 750 ohm and a 650 ohm resistor, I go with the 750 for more protection for the LED.