Yeh you can save your address book to disk by way of exporting it in a csv format saved using Excel, ive done it with my yahoo contact & addresses & outlook express also incredimail.
Not sure about mails though cos i tried & it didnt work hence why i use googlemail now as it archives old mails seperately on site accessible by logging in from any pc plus handy cos it doesnt clog my pc up & it holds 2337mb of storage according to google you never need to delete mail cos of the storage it has.
Hope that helps
