Is it possible to share contacts company-wide on a fileserver (without
installing Exchange) with Office 2003/2007?  The older computers here (Office
2000/XP) were setup up for centralized contact lists using features built-in
to Outlook Express.  Office 2003 and on changed these protocols, and we are
getting more and more workstations all the time that are preinstalled with
2003.  All these users have to send copies of new contacts (or contact
changes) amongst themselves, which seems to me like a substantial waste of
time, and subject to various data inconsistencies.

I've read elsewhere in this forum that .PST files can't be shared.  We don't
need Exchange since our ISP delivers email directly to each employee, and I
can't see spending thousands on Exchange just so we can share contacts.

I have considered upgrading all older workstations to at least Office 2003,
but there's no reason to do so if I will have to abandon shared contacts
completely.  I need to have a new contact sharing system in place, then I can
upgrade the older systems to 2003 or 2007.  

I can't imagine why a feature like this isn't readily available, built-in
and easy to setup with Office 2003/2007.  On the other hand, I'm assuming
that sharing contacts CAN be done in Office 2003/2007 without purchasing
Exchange or other third-party software (if this is not possible, maybe it's
more likely a profit issue).  

Can someone give me some directions where to study up on how to accomplish
my goal?  Thanks!