[olug] Chgrp / chown question

[Tim - DZ]

So I have a set of directories.  Under the root of this set there are
various permissions set and various directories owned by particular
users and groups.

The goal is to basically be able to change a specific owner to a
different owner recursively on all files.  And then independantly do the
same for the group.

Now chown has a -from option, so I can recursively (-R option) find all
files owner by user A and change the owner on just those files to user
B.  

But how can I do the same for groups?