Yes, I'm using a Sony Clie running Palm OS. I sync contacts and calendar fine. You have to install the Entourage Conduit from your MS Office package. It's already there, just go to Applications>Microsoft Office 2004>Additional Tools>Handheld Sync Installer and run that. It should set up your HotSync ability and work fine!
Let me know if you have any other questions, as I've had to reset mine a few times due to my Clie battery getting old and running down.