Pam_USB is a pam_module that allow you to log in w/ a usb-key (or a cdrom/ floppy .. any removable device w/ a serial number or a free space to hold DSA keys.)
This is pretty kool since, this kind of stuff can be usefull. I think about:
- security of course ( using Additional directive )
- or usefull ( for example in POS …)
Anyway i will install this on my notebook since I use it a lot and I can’t always trust the potential users. ( I usually leave it w/ xlock at my work. )