Add a Keyboard Backlight For Under $15

Popular Science has a tutorial on an under $15 mod to add a backlight to the Asus Eee PC keyboard -

Time: 3 Hours
Cost: $13.50
Difficulty: Moderate
Parts

* EL Backlight 3- x 5-inch (All Electronics #EL-13; $4.50)
* Techno Flash EL Wire with IM-4 Inverter (CooLight #TFLASH-BG; $6.00)
* Velcro Hook & Loop Fastener (Hobby Lobby; $3.00)
* Double-sided tape

You can read the tutorial here.