Creating two websites on one model

[eluser]Unknown[/eluser]
Hi,

I use codeigniter for a while and know it quite well, but now I have interesting case.

I need to create couple of websites, which will be basically very similar in case of functionality, but not exactly the same. In this case the best option will be to use the same model in each website but different controller and view.

What would be the best way to do that? I know I can load a model straight from controller (with filepath), but I would like to rather control everything from index.
Any ideas how to overwrite the default libraries path?