When the G1 came out on T-Mobile, a company by the name of Wrike made a free app that would allow Android users to sync contacts with Microsoft Exchange accounts.  Well a recent addition of calendar sync with Exchange has added more features and also now a price too.  Android can handle Exchange mail with its IMAP interface despite it not being a native ActiveSync interface, and contact sync was free with the first Wrike.  For the price of $24.95 and the requirement of Exchange 2007, you can decide if this is a price worth paying to add calendar sync.