Make a pen holder from an empty soda can. Its easy to make, cheap and can hold a yearly calendar as well. My first entry. Also, I don't have a digital camera so I took the pictures from a mobile cam. Hope they're good enough.
Empty soda can
Some playdoh (or any suitable replacement)
Step 1: Cutting up the can
Take an empty soda can. Rinse it out with water so that it removes any traces of soda left in it. Cut off the top off the can using a utility knife. Cut at a plane a little above the upper rim (i.e. the point where the cylinder starts). Also please be careful not to cut yourself while doing this. The easiest way to do it is to push the knife vertically in the top so as to make a hole. Then using the point where the knife meets the can as a lever, twist the knife so that it keeps on cutting more. Kind of how a can opener works.
As you can see in the picture, I had already started cutting the top of the can.
Now you have an empty can and its top. Dispose of the can top.
Step 2: Bending the rim
The reason for cutting at a level above the rim is this. After cutting the top off, simply twist the part above the rim to make a smoother edge. The aluminium is soft enough to be shaped with the fingers. Again if you are not careful, you can cut yourself. Use pliers if necessary. The reason why I suggest using fingers is that you want to keep the can smooth and rounded. Excessive force from any tool will bend and disfigure the smoothness of the can. Also, the aluminium can can(?) crack under excessive pressure.
If there are any deformities still present, use your judgement to press and squeeze (the can) to make it as round as possible.