Login using fingerprint reader
Fingerprint GUI is working just fine in Ubuntu 12.04 Beta1 (LightDM). You can log in, unlock screen, and authenticate everything in the GUI and also "sudo's" in a terminal. I'm using it on an old ThinkPad R52 with integrated SGS Thomson Microelectronics Fingerprint Reader.
Install instructions: Fingerprint GUI
This is available in the repositories as well a sourcefourge
libpam-thinkfinger
ThinkFinger is a driver for the UPEK/STMicroelectronics fingerprint reader. The device is usually found either as a standalone USB device, built into USB keyboards or built into laptops (usually from Dell, IBM/Lenovo and Toshiba).
pam_thinkfinger is a Pluggable Authentication Module that allows the user authenticates through his fingerprint.
The recommended package thinkfinger-tools can be used to acquire, verify and automatically store user fingerprints.
Homepage: http://thinkfinger.sourceforge.net
PAM wiki
This has worked flawlessly for me through Ubuntu 12.04/12.10 with an SGS Thomson Microelectronics Fingerprint Reader.
sudo add-apt-repository ppa:fingerprint/fingerprint-gui
sudo apt-get update
sudo apt-get install libbsapi policykit-1-fingerprint-gui fingerprint-gui
Exit your session, login again and run Fingerprint GUI to set it up [0483:2016]