Answer: I don't know, but I've taken my fair share of post-its, notepads, folders, staplers, staples, staple removers, markers and pens (don't leave me around your cubicle). Sometimes when I'm writing down possible blog topics in my bed, I have to turn and lean on my elbow to make the pen work. It is quite an annoyance. I wish there was a pen designed to specifically remedy that problem.
My wish came true.
Last night while I was organizing supplies in my home studio, I came across an old sketchbook from my college days. Trapped in the spiral binding was a pen given to me from my parent's neighbor while visiting them in Florida a while back. He was writing my father a check from last night's dinner and was showing off his pen. I asked him where he got it and he said it was a gift. I admired it so much that he practically begged me to take his pen. So I did.
I now show to you in all it's glory The Astronaut Pen:
It even writes upside-down and the astronauts use it (in space).