1. Acquire enough cardboard to create 32 11" square pieces
2. Head over to http://www.thingiverse.com/thing:14272 to download the laser template files or SphereGen.exe which will generate the templates for you. SphereGen lets you specify your cardboard thickness, desired width, height, and how much each layer should overlap adjacent layers. If you'll be using the Ikea "Hemma" cord set as your light fixture, the inner diameter should be 1.575 inches.
3. Laser cut all the rings
4. Sort the rings from smallest to largest. (There will be duplicates for most rings because they appear on the top and bottom halves.)
4b. (Optional) Stack the rings to get a feel for how it will look and play with different designs, like rotating each layer slightly to create a corrugation spiral effect.
5. Break out the Elmer's glue and start gluing layers to one another. Be careful to make sure that each layer is centered and you aren't slowly drifting away from the center.
6. Once the glue dries, treat the entire lamp with "No-Burn", a fire retardant spray. I found a bottle for $18 on Amazon. Just to play it safe, I also recommend using a LED light bulb to ensure the cardboard never becomes hot. (Although this is probably unnecessary -- after being lit by a traditional 60w incandescent bulb for half an hour my lamp's interior remained cool to the touch.)
7. Once dry, attach light fixture. I used an Ikea "Hemma" cord set which only costs $5. http://www.ikea.com/us/en/catalog/products/10175810/
8. Plug it in and enjoy!
seejay323 made it!