[Steven Zahm]

@ David

This is a bit complex…

Probably the closest code example I can give is this:
https://github.com/Connections-Business-Directory/Connections/blob/0.8.14/includes/class.metabox-entry.php#L388

That the code that creates the checklist in the admin.

The related function being used is here:
https://github.com/Connections-Business-Directory/Connections/blob/0.8.14/includes/class.form.php#L264

And that calls a couple recursive functions for transversing the category tree and output the list.

It is come pretty old code that is going to be rewritten because it can be done better … but this should at least give you the idea of how to put this together. Hope it helps!