constants and custom config settings

[eluser]fivestringsurf[/eluser]
I have always (when not using CI) typically placed constants and config settings in one file "config.php" and included it at the top of each php page. This has given me access to things like: live vs. local status, constants like: max character length, locations, etc...

Where's a good place to include this basic initialization stuff in CI sticking with MVC philosophy of course?
placing constants in ci's config didn't work...and loading a library with this stuff seems kind of sloppy and misplaced.

Any advice would be appreciated; thank you in advance.