Ubuntu Linux installs just fine on many laptops, but the fingerprint scanners on those laptops are often built for custom Windows security applications. Fortunately, there is a relatively easy way to enrol your fingers and log in with them in Ubuntu.
The OMG! Ubuntu! blog points to a repository you can add to your system from which you install a few packages (remember: Ctrl-Shift-V pastes into a terminal). As noted at the original post, removing that fingerprint repository requires you to manually re-install a policykit package. It sounds scary, but you probably won't have to worry about removing the repository. Once you've pasted and run those two lines, you're all set to run Fingerprint GUI, enrol your fingers, and set your fingers to log you into your system or use your finger to enable sudo commands.
If you're a ThinkPad owner, you might need to do one or two more things to enable your fingerprint. They're linked in the original post's comments, at Frontier Computing and Network Services and ThinkWiki.
Do you have fingerprint authorisation working on your Linux system?
[How To] Get Your Fingerprint Reader Working in Ubuntu [OMG! Ubuntu!]