Building a site with CodeIgniter

[eluser]ThomasOwens[/eluser]
[quote author="inparo" date="1215060976"]Yes, all you would need to do it copy index.php, rename it to say forum.php. Then you create another copy of the applications folder, name it forum_app or something similar and change the application folder path in forum.php .[/quote]

I'm still left with two related questions. First, how would I handle sessions across apps? Second, where would I put my cross-app code, like my user-related code, that applies to every single app?