Microsoft Outlook

The solution for Google Apps fans who are still using Microsoft Outlook on their desktop computer has arrived. With Google Apps Sync for Microsoft Outlook, you can skip using Microsoft Exchange Server and get all the benefits (read: it's free) of Google Apps Server while keeping the familiar interface of Outlook. Your data is automatically synced between Outlook 2003 or Outlook 2007 and Google Mail & Calendar.

Here is the full introduction from Google: