From the official Google Blog:
One of the hardest parts about switching phones is getting your address book and calendar to your new device. We're making that process a little easier by releasing a beta version of Google Sync for the iPhone and Windows Mobile phones as well as a contacts-only version for phones that support SyncML.
For iPhone and Windows Mobile devices, Google Sync allows you to get your Gmail Contacts and Google Calendar events to your phone. Once you set up Sync on your phone, it will automatically begin synchronizing your address book and calendar in the background, over-the-air, so you can attend to other tasks. Sync uses push technology so any changes or additions to your calendar or contacts are reflected on your device in minutes. The connection is always on so you don't have to manually sync your phone after Sync has been set up. This means that when your colleague changes the time of the TPS report cover sheets meeting, you'll know about it right away.Read more...
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