"Well, I've seen pens made with almost anything you can imagine, myself am responsible from making pen blanks from mots weird things however, and as far as I recall, I'm yet to see a pen made from a penis.
Jokes aside, how in the heck would one advertise such a pen...???"
Here's a couple. They are Bully Sticks (pizzles), as mentioned previously. The first pens the ladies pick up (seriously). Made and sold six of them. All but one to ladies.