I've had this idea for a long time and when I read about the Coffee cup challenge thought this would be the time to let this idea become reality: The coffee cup sphere lamp!
I must admit it isn't completely original. I just saw the same idea posted in another Instructable here, and I can remember seeing something similar in a windowshop as decoration but hey...those aren´t my story, so let get to work!

Step 1: The Ingredients

So start drinking a lot of coffee, especially the bad tasting stuff at your work or school. Save the cups.
Ehmm...to be honest...I did not had the time to wait until I had collected about 300 necessary cups so I went to my local supermarket and bought them. (however I drink way to much coffee, in such quantities that there was a time it was my main source of inspirations as you can see on my website)
I rather would have had paper cups but they only had plastic ones, so I sticked with those.
Besides that Instead of using glue I picked up my stapler and ( a lot of) staples.
Further more you'll need electric wire with an attached socket, an energy-efficient lamp (with normal lamps I'm afraid the heat will meld the plastic), some (3 or more) pinbolds, a big washer and some small ones.

Let me list that;
-300+ cups
-a stapler with staples
-electric wire with socket
-energy-efficient lamp
-pinbolds
-big washer
-small washers
-a heatsource (a lighter or something like that)
-A sharp metal pen (for instance a scriber) with the thickness of the wire

Step 2: The Base

OK start with stapling three cups together, this will be your base around which you'll build the rest.
I found out that stapling the staples nearest to the bottom first will work the best. Changes are,with stapling the upper first, that the plastic will rip. I didn't mind because it was kind of a ghettostyle work and in the end, because of shortage on staples, I only did the lower ones.
Next time, with paper cups, I think I would try some glue. Just experiment yourself.

Step 3: Building On...and On...and On...

Now you have the base you can build on around it. Because of the tapered form of the cups you'll end up automatically with a sphere (kind of).
I started with a system of weaving the edges under and over each other, as you can see in the picture of the base, but later on, I got lazy and only put the edge of the cup under the previous one.
Besides that I ended up (because of my laziness, and the will to finish it of in one evening) with some bad fitting. So the top part of the sphere is kind of messy and the form more resembles an egg than a sphere. But, so what,... even Brancussi thought the egg was the beginning form of the universe huh?
There isn't much to say about the ongoing just staple on until you've got blisters on your fingers! Just leave one hole open for the last cup.

Step 4: Placing the Lamp

So now you take the last cup, heat up your scriber and burn a hole in the bottom. Place the big washer under the underside, tie a knot in the electrical wire and put it through the hole from the outside. Attach it with the split bolts trough some holes (which you'll have to meld with the scriber first off course) with the small washers in between to prevent them slipping through. Now you can easily remove the cup if the lamp is broken.
Never mind the paper clips you see on the photos before, those where a first try to fix the last cup in place: It didn't work.

Your lamp is finished (only have to hang it on the ceiling and put the wires on the electricity off course. Be careful with that!).

Let it burn!