Message Waiting indicator for Exchange 2007 Unified Messaging

A pretty common question I am asked is how to support the Message Waiting Indicator (MWI) on traditional telephones when you move the mailbox to Exchange Server 2007 using the Exchange Server 2007 Unified Messaging server role. I just learned about a product that sounds really promising from Geomant. They provide a Messaging Waiting Indicator function and an SMS function that is supposed to integrate with Exchange 2007.