The Yubikey is a phenomenal new device that's smaller than most memory keys that when plugged into a USB port and the loan button on the case is pressed, a one time password is generated and entered. It does this on any HID enabled operating system including my beloved Mac OS X and FreeBSD without extra drivers because it shows itself as a regular USB keyboard. It's so beautifully simple!
The best part is that the API is open and accessible from a number of different programming languages such as Ruby, PHP and Python (not sure about Perl just yet).
In the coming weeks I'm going to try to implement my Yubikey into my Ruby CMS. I'm really excited!