Hi guys,
I thought I would give a bit of a shamless plug to a project I started on a couple of weeks ago. otp-sso
http://code.google.com/p/otp-sso/This is a java based webapp (glassfish) that will authenticate users against yubikey, scratchcodes and google authenticator created totp codes (straight from the RFC). This is still in early development (and looking for co-developers if anyone is interested), but as of right now it can be used (and I am using it for) Google apps SSO/SAML, Freeraduis authentication (linux, windows and wireless auth) as well as having its own (really early start) web interface login. This is not something for the production environment just yet, but if you are looking for an easily working SAML / Google Apps SSO solution for Yubikey it does this. I should note at this stage it does not talk to yubi's own val server, but it runs its own version of the now defunct yubikey j server.
Comments/Feedback welcome.
Jake