If own a iPhone, Windows Mobile, SyncML, or BlackBerry phones; you can now synchronize your Gmail Contacts and Google Calendar events using Google Sync that 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, explains Google Mobile Blog.
To get started, Google Sync must be enabled for your domain from the Google Apps control panel. For devices that support the open SyncML protocol, Google Sync will allow for two-way contacts synchronization. If you're a BlackBerry user, try Google Sync, rest all visit m.google.com/sync is already available, explains Google Blog.