Most configurations files are stored in /home/username/....
So for mozilla specifically, you could copy the /home/user/.mozilla directory to all the other users home directories.
This would copy a lot of things, including the history though. You could be more cunning by
setting up symlinks for only the config files you want in .mozilla to a central repository. You have to be carefull doing this sort of thing though, as any user could change the settings - unless you don't give read/write rights to the files.
I do this this for sharing my Thunderbird email box and setings between my Windows 2000 and Linux partitions on my laptop (I have to use Photoshop, so need to use Windows sometimes!). You can even share bookmarks and so on, but it takes a while to setup. Only for the really bored and those who don't get out enough.