Upload image without media uploader

Hi,
I’m creating a portfolio site and I want users to upload four images using a custom post type. I’ve got everything working using the excellent MU Plugins for custom post types. But the upload image still invokes the media uploader and this has confused the pants off my Beta testers. So I want to simplify it and have a browser upload version within the custom meta itself – so no media uploader pop up.
Is this possible with WP 3.5? I’ve searched and searched but cant find a solution!
Thanks