At work, we've got roaming profiles. I've just spent 20 minutes logging on, because I have a 7-8gb shared mailbox in my outlook.ost; and that makes things unhappy.
What beggars belief is how you move your outlook.ost.
Call me stupid; but I rather thought we'd mastered the basics of a "move" file within our operating systems.
Apparently, the outlook 2007 team has some reason to make that impossible to do - the user interface fights you every step of the way.
Unless you disable a tonne of options which should have no bearing on your ability to move, copy, or change the location of your offline mailboxes; Outlook will not let you touch this setting.