If you use Mac Entourage user then this is for you!!
To take advantage of the latest innovations that Exchange 2007 has to offer, Entourage 2008, Web Services Edition uses Exchange Web Services to communicate with Exchange Server. In this update, Entourage uses Exchange Web Services to provide several calendaring improvements. The update includes support for notes, tasks, and category synchronization with the Exchange Server.
Microsoft Entourage 2008 for Mac, Web Services Edition uses Exchange Web Services as the primary protocol to communicate with Exchange Server. In addition to several calendaring improvements, this new version of Entourage synchronizes notes, tasks, and categories with Exchange Server. This update also enables logging that can be used for diagnostic purposes.
You can download it from here.