[gdm-list] Two-Factors GDM login screen?

[Alessandro Bottoni <alexbottoni yahoo it>]

Hi All,
is it possible to have a two-factors login screen with GDM (without
hacking the code)?

I would like to have a login screen with the following fields
("connected" to some underlining PAM module):
1) Username/Face browsing
2) Static password
3) Dynamic (One-Time) password (generated by a OTP generator like some
type of RSA SecurID or some type of Aladdin eToken)

How do you configure GDM to get this result?
Which PAM module can be used to manage dynamic/OTP passwords?

Thanks in advance for your help
-- 

Alessandro Bottoni
Website: http://www.alessandrobottoni.it/

"In mathematics you don't understand things. You just get used to them."
     -- John von Neumann