How do you register cleanup code to be run after script execution?

[use dmgass at hotmail dot com]

I'm writing a module and when it is imported by a script I want some code
automatically executed when the importing script is finished executing.  I'd
like it to execute before interactive mode is entered when executing the
importing script from the command line.  I don't want to have to impose that
the importing script must call a function at it's end.

Any help is greatly appreciated!!