ALLOW NON-ADMINS ACCESS TO SYSTEM PREFS

Here's a great way to allow standard users to change settings normally reserved for admin users (such as energy settings, date & time, etc).

You'll need to be comfortable with the command line to do this but it's fairly straightforward:
Using your favorite text editor, sudo into the authorizations file at /etc/authorization and change as follows:

Old

<key>system.preferences</key>

<dict>
<key>group</key>
<string>admin</string>

<key>shared</key>
<true/>

<key>allow-root</key>

<true/>
</dict>



New



<key>system.preferences</key>
<dict>

<key>group</key>

<string>staff</string>

<key>shared</key>
<true/>

<key>allow-root</key>
<true/>

</dict>

Save changes and exit the file.  This allows non-admins access to ALL system preferences except Accounts.   As an admin, you may not want standard users to be able to change the startup disk-- you can change that by modifying that specific preference pane -- again, via the command line:

sudo chgrp -R admin /System/Library/PreferencePanes/StartupDisk.prefPane
sudo chmod -R u=rwx,g=rwx,o=r /System/Library/PreferencePanes/StartupDisk.prefPane

ref this post on MacNN Forums:
http://forums.macnn.com/90/mac-os-x/216189/editing-etc-authorization-file-panther-how/