Syncing Touch with Entourage

Do you mean for email? Do you have IMAP email service? If you're using POP email, then you'll have to change the setting in accounts on entourage so that messages do not get downloaded from the server--that way they remain on the server and can be downloaded both to your touch and your computer. Be sure also to enable "delete messages from server when put in trash" (or something like that) because otherwise you'll fill up your server with messages--that will delete the ones from the server that you no longer want.