[Zope] List All users with a given permission

I suddenly find myself with a need to populate a list box with all users with a given permission on a particular object. Is there any nifty method hidden away to do this? Or would I be reduced to crawling up the tree looking for userfolders and iterating over the contents (could be a bit sluggish with 3000+ users...) Perhaps I'll just require tying the username and verifying on form submission :-) ___ // Zen (alias Stuart Bishop) Work: zen@cs.rmit.edu.au // E N Senior Systems Alchemist Play: zen@shangri-la.dropbear.id.au //__ Computer Science, RMIT WWW: http://www.cs.rmit.edu.au/~zen