How to restrict user access?

[comp question]

I need to restrict a user to access only one directory on a machine.  How 
can I go about doing so.  Currently the directory is wide open and owned by 
group other.  All users are supposed to have access to this directory, which 
is why the group is set that way.  It seems the best way  to get this 
accomplished is to make a new group and add all existing user to this, as 
their secondary group, and make it the new users primary group.  Does this 
seem practical, or is there a better way?  Thanks.

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp