How about this possibility for Outlook 2003 with SP2
1) Use the ForcePSTPath and ForceOSTPath values. (PST to network or local
location. OST should remain local because Microsoft doesn't support the use
of PST/OST files from a network drive and you really want to ensure that if
the network connection goes south, that Outlook works.)
2) If you look in the Outlook 2003 administrative template file there is a
setting called "Cached Exchange Mode (File | Cached Exchange Mode)". Now if
you set this policy to Download Headers, it will set a registry value in the
HKCU Policies section and enforce it. Not so hot when you want to give the
user a choice to switch back to Full Items. What I'm thinking is that you
can create/modify the administrative template so it creates the registry key
as a preference (goes under HKCU/Software/Microsoft rather than Policies
section).
Now switching it this way means that a new windows xp user profile will have
a registry key that forces Outlook 2003 into Header Only mode to start, but
gives the user the option to switch to full item later. In theory this
should allow them to get to work faster and you do not incur extra bandwidth
utilization when going after that OST file on a network share.
/neo
PS - I'm assuming that Exchange 2003 is the backend.