How do I put myself in the staff group?

Question

I have been trying to optimize my iMac 24 ever since I upgraded to OS X Lion.  Tons of SBBOD and general slowness.  I went through all the basics and things are much better.  This included booting in to the recovery partition and resetting my home folders permissions back to the defaults for Lion.  I did this because I noticed that the permissions on my stuff in my home folder still had me in the group that was identified by my username - a throw back to a prior version of OS X.
After running the procedure, here is what my home directory looks like:
iMac24:~ hstan$ ls -l
total 2032
-rw-r--r--@  1 hstan  staff  518912 Sep 23 15:26 Apache Documents
drwx------+ 13 hstan  staff     442 Dec 20 08:11 Desktop
drwx------+ 62 hstan  staff    2108 Dec 16 15:14 Documents
drwx------+  5 hstan  staff     170 Dec 20 08:09 Downloads
drwx------@ 73 hstan  staff    2482 Dec 21 10:22 Library
drwx------+ 19 hstan  staff     646 Nov 28 21:25 Movies
drwx------+  7 hstan  staff     238 Mar 26  2006 Music
drwxrwxrwx   6 hstan  staff     204 May 27  2008 News.framework
drwx------+  8 hstan  staff     272 Oct 15 14:48 Pictures
drwxr-xr-x+  6 hstan  staff     204 Sep 24  2010 Public
drwxr-xr-x   8 hstan  staff     272 Nov  6  2010 Sites
iMac24:~ hstan$
I did successfully reset all the permissions in my home folder to what Lion expects as above.  Popping a terminal, I ran the 'id' command and this what I see:
iMac24:~ hstan$ id
uid=502(hstan) gid=502(hstan) groups=502(hstan),401(com.apple.access_screensharing),12(everyone),33(_appstore ),61(localaccounts),80(admin),98(_lpadmin),
100(_lpoperator),204(_developer)
How do I put myself back in to the staff group?  I know that I have to do it via the shell - just don't know to do it.  Also, once I do manage to put myself back in to the staff group should I delete the gid 502(hstan)?
I do admit that things did indeed smooth out after I reset my home folder to the default permissions.  Just stuck on this last bit of cleanup work.
Thanks!

Answer 1

Realize this thread has been dead for a while, but I was running into permission problems on 10.8.0 and managed to find this fix. I can't remember when I last did a clean install, but it was before the transition to staff as the primary group, so the account is pretty old.
I used Directory Utility to change the primary group on my account (twillis) from twillis to staff as described. I then rebooted into the recovery partition and ran resetpassword to repair the home directory permissions and also rain repair permissions from Disk Utility. Finally, I used chgrp to manually change groups on some things like apps and frameworks that were in twillis (this looked like the right group to use based on context). Process went smoothly and worked as expected with one glitch.
I have now found a few situations where files are still created or changed to the twillis group. According to id I am no longer in that group (as I would expect):
[twillis@elle] ~ 39 # id
uid=501(twillis) gid=20(staff) groups=20(staff), 401(com.apple.access_screensharing), 12(everyone),
33(_appstore),61(localaccounts),79(_appserverusr),80(admin),81(_appserveradm),9 8(_lpadmin),
100(_lpoperator),204(_developer)
As an example, unzipping a zip file with the Finder creates files in the group twillis even if the zip file and its contents were in staff. Another example involves AlbumData.xml in the iPhoto Library package: I can chgrp it to staff, open Aperture, edit a picture, and quit and AlbumData.xml will be back in twillis on exit (doing a simlar set of steps with iPhoto though does not change it).
Should I have removed the twillis group with Directory Utility too (using the "-" button right under the left column of the window) --- twillis is showing up listed in Users&Groups too in a "groups" section after the accounts, so perhaps I can delete it from there too? Or is there some other state that is still associating the twillis group with the twillis account that I also need to change?
Thanks,
tw