Where to put plain object classes?

I may have misunderstood your question here - apologies if this is the case, but take a look at Loader Class Documentation about passing parameters to models.

Edit: Just noticed that this had already been suggested by includebeer here.

That applies to the loading of libraries only and you are limited to just one parameter. Unless I am missing something, you cannot supply any parameters at all when loading a model. Also, I find it curious that CI doesn't use call_user_func_array for loading libraries so that one can specify multiple parameters to a library constructor that accepts multiple parameters.

I stand corrected, yes that applies to library only. With that said the Loader class can be extended to allow for this.

Jamie Bond
Full time International Development undergraduate.
Part time website developer.