Contacts

No can do. The contacts have to be in phone memory. In Messaging you can switch the message store to MMC instead of phone memory, but no similar functionality exist for contacts.

You can do a backup (of all that is in phone memory) to an MMC in the phone, though, but that's presumably not what you're after.

Calender, contacts and documents can only be in phone memory.

The best thing to do is to back up your contacts, calendar, etc. to your PC via bluetooth.