What it is:
ClearLock is a transparent screen locker aimed to make the computer tech/system admin's live easier by providing a way to disable input to a computer while still allowing you to see what is going on. I could go on but I think you all get the idea by now.
What it isn't:
ClearLock is not a security system. its purpose is to keep meddling users from screwing with the computer when you are fixing it. It will not keep your computer/data safe from someone who is determined to get at it.
Config can be performed in BartPeBuilder/Ubcd4WinBuilder by using the config button in the plugin manager or directly inside PE by usging the ClearLock config shortcut. See the readme.txt for details.
The ChangeLog for ClearLock.exe can be viewed here