Execute script automatically on every page?

[eluser]jedd[/eluser]
Ah, good, okay. It's not the kind of thing that you want to extend controllers for, then.

It'll be a routing / htaccess hybrid I presume. That side of things confuses me, particularly if you're going to have to re-write your base_url to match the domain the user came in on (or was redirected to). But now you've described it thus, it'll be easier for one of the apache/CI-routing gurus to give you some pointers.