I use PKI login for SSH on my home and work. I use a DSA key on a USB memory stick. Since I don't have smart card hardware at either location -- and setting this up entails a lot of research that I haven't finished -- I'd like to get my feet wet by setting up PKI log-on for desktop sessions on my home network.

Is this possible in Ubuntu? I realize it's less secure than a proper smart card infrastructure for various reasons, but it seems like a good learning exercise and a step up from passwords.