I just read a Walt Mossberg's Mailbox article about how to move from a Windows PC to an Apple Macintosh when you have a great deal of information in Microsoft Outlook, and it reminded me of the work around I came up with recently.
Christy recently migrated from a Windows XP based laptop to an iBook G4 with Leopard. And she was using Microsoft Outlook on the PC for email and contacts.
I moved over all her email using Google GMAIL's IMAP service. This was pretty easy, because once I had the IMAP account configured on Outlook I could just drag and drop the emails she wanted on her Mac. Then I fired up the Mail client in Leopard and configured it for the same IMAP account, and I was done.
I figured I could use the export functions in Microsoft Outlook to get me a contacts file that would import into Apple's Address Book, but every file I tried ended up hanging when I tried to import on the Macintosh.
So, I came up with this work around.
I went into Microsoft Outlook's contact view on the PC, and did a select all. And then did a right mouse click to Send vCard of all the selected contacts. This created a new email message with all her contacts vCards. I then selected all the 'attachments' and saved them to a folder locally on the PC. I then copied the folder to a USB flash drive and moved them to her Macintosh. She then clicked through that folder and added the people she wanted into the Leopard Address Book. Pretty easy and it also cut down on some clutter in her new Address Book because she picked just the vCards to import that she wanted.
Walt suggested a $10 tool from Little Machines' O2M (Outlook To Mac). I haven't used the tool but from what I read on their site it appears to be a possible alternative solution.