Comment 5 for bug 203973

There's a new README as of April 10th that states:

libpam-thinkfinger for Ubuntu
-----------------------------

In order to enable authentication by fingerprint, you will need to
run the /usr/lib/libpam-thinkfinger/pam-thinkfinger-enable script.

In order to acquire new fingerprints for login users you need
tf-tool, which is included in the recommended thinkfinger-tools
package and is also used to verify fingerprints.

 -- Scott James Remnant <email address hidden>, Thu, 10 Apr 2008 16:49:04 +0100

That script should handle pam.conf for you. If it does not succeed, please report a new bug!