I am today using an LDAP-server to sync contacts with my iPhone. It does not give me all the functionality I am looking for. I am thinking about setting up a contacts server using CardDav, but I am not sure if it will really solve my problem: Does the iPhone automatically look up contacts from the synced CardDav-server? Does it behave like my contacts were synced from iTunes? Ie, if I have added "Tom Jones - 333 333 333", does it a) display Tom Jones if 333 333 333 is calling me?