A while back Uncle linked to somewhere that linked to this article at The Gear Journal about taking a couple cheapish Zebra pens and combining them all together along with a Fisher Space Pen cartridge. Having grown up loving all things NASA and dreaming of having a Space Pen, and having an extra couple dollars in my pocket, and having a thought in the back of my head that I ought to get a pen to carry around in my pocket (after all, I have a notebook). While later investigation revealed that it isn't really "tactical" like he initially said, I approached it more from the "space pen" and "cheap entertainment" angles than the "ultra durable impact weapon" angle.
So I followed the instructions on the Gear Journal, and now I have this:
A clean and classy looking pen that can write... IN SPAAAAAAACE! Total cost was around $15. Yes, I am a geek.