In short it works like a charm. Very cool to login via gdm, virtual terminal and the screensaver with the swipe of my index finger. Of course I could not resist trying my other fingers and none of those worked as hoped. The Thinkpad T43 I use is a company laptop, but after following the How to enable the fingerprint reader page on the excellent thinkwiki.org site, it was very straightforward to get working. Needed to "up2date pam-devel", adapted the Fedora install script to RHEL4, and followed the xscreensaver howto there simply porting the 4.22 patch back to RHEL4's 4.18 version (which I ended up wrapping into an rpm: xscreensaver-4.18-5.rhel4.10.rhis.src.rpm).