Hardware For Protecting Your Passwords?

AstroBush asks: "I was reading this article which raised a very interesting question: Hardware keylogging devices now exist which can record all output of the keyboard regardless of operating system, permissions, or any software-based controls. How can I protect myself from having a co-worker (or student, thief, ex-wife, etc...) using one of these devices on my machine? Is there any keyboard available which encrypts output before it reaches the computer?"