For a long time I had wanted to be able to manage the groups on my *nix OS so that I could better manage access to files. The functionality is very limited in the OS X gui, and I couldn’t find command line stuff that worked. Finally, I found out that some of Apple’s server utilities are available for download for free, and work with a regular install of OS X. One of the utilities is called workgroup manager. It allows you to create groups and add users to them. So I can now create groups for specific projects or purposes, add the users involved to the related group, and make all related files owned by that group so the users have proper access to those files.