The iPhone sync process for contact information, calendar events, and bookmarks is bidirectional with the support applications on a Mac or Windows PC.
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Office for a Mac includes Entourage which is very much like Outlook. Entourage combines an email client, calendar and address book.
The supports applications on a Mac for syncing contact information, calendar events, and bookmarks is Apple's Address Book application for contact information, the iCal application for calendar events, Safari for bookmarks and Entourage for contact information and calendar events. Entourage data is actually synced with Apple's Address Book application and iCal which the iPhone syncs with.
You can sync your iPhone with the Address Book application and iCal or you can forward all Outlook contact information as separate vCard files attached to an email message sent to an email account that you access on your Mac - with Apple's Mail application or with Entourage. The received vCard attachments can be saved outside of the received message to a folder created on your Desktop or your desired location. Use the Address Book application to import the vCards from this folder to the Address Book database.