What is the best way to implement hierachical categories in the current version?

I know it will not be available until the next release (v6 - Q2/3 2011) but we cannot wait for that version and need to be able to associate a page to multiple hierarchical categories for programmatic use.

I have ruled out tags/current single categories, related documents etc because the way we would like it to work is:

- Create a new page anywhere on the site
- From the forms tab have a checkbox tree view of the hierachical categories
- Tick all categories that apply and save page
- From a custom user control for example be able to search for all pages that have a specific category association (no matter what the parent node is)


The current Related documents functionality is the closest functionality to what we want but is too slow - added one at a time - not a multi-select treeview.

The way I am looking at doing this currently is to use a custom form field in a similar way to this: http://devnet.kentico.com/docs/devguide/index.html?developing_form_controls.htm


But the control will be a TreeView and will fetch data from a config file or custom database table and I will store the selected values as a comma delimited list (as form controls store single values not mulitple values).

Does this sound a feasible approach - any alternative ideas appreciated?

Thanks,
Lee.