I thought of 2 ways you can do this:
By setting up a wrong model for your laptop keyboard in xorg.conf ?
By installing Lock-keyboard-for-Baby
`Lock-keyboard-for-Baby or lk4b in short, is a small program which locks your keyboard but leaves your mouse free. I wrote it because my niece likes to bash away at my keyboard whenever she sees me sit down at it. Keys typed on a keyboard can have disastrous consequences and I didn't want to lock my screen all the time with a screensaver.
When started, lock-keyboard-for-baby opens a small window which grabs the keyboard and echos keys which are typed. By default, it tells you what to type to quit ("Quit Now").
Unlike a screensaver, your screen is not blocked and the mouse still partially works, so you can still see what is on your screen - keep watching tv / video and/or read a document using the mouse to scroll.`
· GTK >= 2.x
· perl GTK2 bindings (perl-gtk2 or gtk2-perl depending on your system)