Tamper-resistant school setup?

I work in a school. A common problem here is that younger students love messing desktops up. In Windows, this problem can be solved particularly by restricting the access to the control panel. But I think that Ubuntu, which is our currently used OS, can provide a greater control over student PCs. In fact, I even like that they play this way, so rather than restricting it'd be better for me to undo their changes later. The versions are 9.04 to 10.04, but it's not a constraint.

So yes, I would like to have a fresh user environment after the boot. The solution should not go too far, e.g. boot-stage image cloning, and there must be a possibility to install and keep installed new software. As you could guess, I'm not experienced in Linux, but I do know the basics and I have some programming skills (c/c++/c#, windows). I don't know where to start. Is there a folder or files one can erase to get a fresh user profile? May be there is a solution already?

Cheers!

Simply restrict the permissions of the student logins so they can't mess with the administration options, no access to the terminal etc.

It sounds like you might be after a kiosk mode?

Ok, now I have something to google for :) Thank you. But what with self-restoring profiles? As I said, it's a preferred option.

I can't see any reason why an rc script couldn't delete a profile, and move a copy into its place; it would be a pretty simple script.

I am sure others can and will come up with a more elegant solution.