custom field rich text editor?

I’ve been playing around with custom fields lately (also using the beautiful custom field gui plugin), since I really want to have another post-field within the write post/page section. This way I can manage WordPress as a CMS for dummies more easily, and make better use of templates without having to add more category hacks to the code. The thing is that I haven’t found a way yet to add a rich text editor (tinymce) to a custom field textarea, which would make the life of non-html digi-dinosaurs wordpress users a lot easier I’d think. Does anyone have a solution for this? thnx