Public computer control

[Bruno Wolff III]

On Fri, Oct 28, 2011 at 12:59:10 +0200,
  "antonio.montagnani at alice.it" <antonio.montagnani at alice.it> wrote:
> We are installing linux on public library network
> 
> I have two easy questions:
> 
> 
> 1) how can I control time of a session, i.e. to have logout automatically after 
> a certain time from login?? 
> 2) how can I make all personal data flushed at 
> logout??

You might want to look at xguest for the second part.