One of the local shops gave me a Benchmade pen. At first I assumed it would go in the junk drawer but after playing with it, I realized it does have its place, so I take it anywhere I can't take my handgun and knife. I also have it with me every time I fly.
If you know how to use an impact weapon/kubaton correctly, you can do a lot of damage with one of these pens. I don't know about all of them, but the Benchmade is high quality and has some sort of hardened tip, similar to that on my auto center punch I use for some quick end plate staking on my ARs.