I made this before I made the instructable, so it might not be clear.
If you want me to start selling them on ebay, let me know.
Step 1: Get your legos
-a 2x6 lego brick
-a 2x6 matching lego panel
-small flexible insulated wire
-1 superbright LED (white is nice, but you can get a color to match a brick)
-a switch (i used a small toggle switch from RadioShak)
-3 LR1130 button cell batteries.
-needle nose pliers
-something to make the holes in the plastic for the LED and toggle switch
Step 2: Prep the brick
then, using any method, make two holes in the ends of the brick. the hole for the LED should be small, and steadily make it bigger, until the LED fits snugly in the hole.
make a hole for the switch, just larger than the threads. put the switch in, and screw on one nut(or two). dont make it too tight.
Step 3: Electrical
IMAGE 2 - on the left should be the stack of two batteries from image 1. run the wire coming from the top of the two to the bottom of the third. run another wire from the other end of the battery, and wrap it in electrical tape.
IMAGE 3 - very messy, so here is what you do:
1) run a wire from one of the switch terminals directly to the LED.
2) run one end of the battery pack you made to the other terminal of the switch, and the other end of the battery pack to the other LED connection.
3) flip the switch. if LED does not light, check wires to make sure there are no wires crossed anywhere. if still no light, swap the battery pack connections around so it is reversed from how it was. LEDs only light in one direction.
4) when all is correct, fit it all inside the lego brick. the batteries only fit if they are not all stacked.
Step 4: Finishing touches
1 - tape (so you can replace batteries)
2 - glue (you wont be able to replace batteries, but it looks nicer.
Step 5: Some quick tests
IMAGE 1 - the lego LED light is on.
IMAGE 2 - this is the Lego LED light and a mini maglite shining at a wall from 1.5 feet away. the LED is the light on the left
IMAGE 3 - once again, the Lego LED light and the mini maglite, STARING DIRECTLY AT THEM from 10 feet away. the Lego LED light is on the right here.
POST PICS OF YOUR LIGHT WHEN DONE!