Thanks for helping me out with understanding what it is and exactly does! it's great and very informative. also thanks Andy for helping out as well!

Thats cool. I know what it looks like now and what it really does! Thanks guys!

Good post, should hopefully educate/help a few people, but I'll point out 2 things.

An autopen can hold any pen except a fountain pen (because fountain pens do not work at a 90 degree angle, which is the angle the autopen machine holds a pen at). This theory of "only holding thin pens" has cropped up a lot lately, and its just not true. Biro, Sharpie, marker, etc etc can all be used with an autopen.

Also an autopen can be programmed with many different matrix stencils of an autograph, not just the one.

I've seen some questions around about how an autopen works, so I was looking to find a picture of one. This is probably the most common version of an autopen. I think they are quite clever machines, eventhough I hate them... It's basically a normal pen connected to a machine and programmed to write one specific signature. They are quite easy to tell, since it doesn't work with any 'thicker' pens they are usually made with ballpoint-similar pens, so the signature is quite thin. And it always comes to a very apprupt stop at the end of the signature unlike a genuine one.
If you want to see how one works, watch episode 107 of 'Commander in Chief', they use one and show you exactly how they work. Quite fascinating if you ask me...