The YubiKey is a small, relatively inexpensive, USB hardware crypto token that can be used for 2-factor authentication and to generate One Time Passwords. The infrastructure to support it is all open source, and the OTP validation code can be made very lightweight and embeddable. My purpose in proposing this talk is to make the hacking community aware of it in an effort to lower the barrier for using One Time Passwords, and to help foster open source 2 factor authentication.