secure access

[Snoop1990]

Hello,
I search for a possibility to secure a public computer. The computer is used to present new software. So the user should be able to use the software, but he should not be able to do anything. Maybe it is possible to create a restricted user and when I open this User whether over vnc or directly, there should only be that one program, so the user can work with this in fullscreen mode but nothing else.
Any ideas ?

[RobinVossen]

chrootjailing is what you need.
This is a hard subject. Doing it wrong is very dangerous..
I am also looking how this works. At this topic.
I really think that some Guru must get some time off and write a good Tutorial about this :P