first you will need is solder iron and solder ofc. then you need 3 white led (its about 5 cents each=15 cents , it depends where you buy, i bought it in Serbia and here is 10 cents per one)<, then you need resistors for led i used 82 ohm resistor ( in serbia its 10 for 9 cents, 110=1 $) and you need usb cable from old computer or phone.
1st. step is to cut off one end of usb
2nd, then you solder LED to resistor ( end of one resistor to cathode of led, shorter leg) then you solder other end of resisotor to black (or blue in my case) and anode (longer) of led to red wire on usb
repeat this step 2 more times ( or 10,20 , depends how much led you want) and you done it.
also i used my cell phone wall charger , you can use it as standard lamp, and you can design housing,.....
P.S. sorry for bad english, english is not my first language.
i forget, next i will show you how to do electrolysis