EL wire stands for electroluminescent wire. This wire can easily be attached to clothing or other materials that bend or have moving parts. And it comes in fun colors and shapes.
To add that that EL glow to your projects, you basically need 3 things
1) a long strip of EL wire
2) an EL Inverter Battery Pack
3) an some batteries
Or consider getting a starter kit with both the wire and the battery pack.
The first think you need to know is that YOU CANNOT USE just a standard battery like you do with most LED eTextile project. You MUST get an INVERTER battery pack. This makes the power source for your eTextile project a little harder to conceal (and in the case of my hat a little clunkier)
Sparkfun has an inexpensive inverter and lots of fun colors available in its selection of EL wire .
In my project, I ended up creating a design that used the whole length of the green wire I happen to have handy. However, you can cut it any size you want, as long as you reseal the end with hot glue or other similar substance.
But it must be powered by AC (alternating current) -- the same type of power that comes out of the electrical outlets in your house. But since it would not be practical to have your e-Textile projects plugged into an outlet, you can get portable power but using an inverter battery pack. The inverter changes the direct current power that batteries produce and 'inverts' or changes it to AC power needed by your EL wire.
Your EL inverter/battery pack will include a JST connector that connects with the JST connector on your EL wire. Most EL inverter/battery packs contain a button that changes the look of the EL wire from 'ON' glowing, to 'Chasing" or "Blinking", to OFF, every time you press the button.
Here is a short video demonstration from SparkFun.