Google Apps Migration for Microsoft Outlook allows you to migrate email, contacts and calendar data from Microsoft Outlook profiles and PST files to Google Apps. The program allows you to perform a user driven individual migration, selectively migrate email, calendar or contacts (or any combination thereof), and more.
v2.1 [Apr 28, 2011]
Google Apps Migration now supports using 3-legged OAuth for migrating users' mail, contacts, and calendar data to Google Apps. When running the migration utility, users can now sign in to their Google Apps account via a Single Sign On (SSO) system—using their current service's login credentials, rather than their Google Apps credentials.
3-legged OAuth is also more secure since users can explicitly grant access to their account and then revoke it any time.
It also supports a new command-line flag to disable calendar fanouts, creating events only for the user whose data is being migrated—without adding the event to calendars of other attendees. This new flag is useful when performing test migrations.
