How to load my classes whenever, wherever without having to include/require them

[eluser]sneakyimp[/eluser]
Thanks for your reply. This code also looks more or less identical to my code. I guess I'll re-post the questions I originally asked to see if maybe someone will bother addressing them:

1) This is an odd place to put a function, no? I vaguely recall that it was necessary to define the autoload function sufficiently early that it properly located my classes for use in a controller.
2) If I need to upgrade CodeIgniter, will this be preserved?
3) Is there some other, more ‘correct’ way to do this?