From the quick links drop down menu go to ".address book". Then click on "Settings". On the right hand side beside Select, choose "Export" from the drop down menu. The export options will now be shown, you can only export to Outlook Express format though.
Then click the "Export" button just above the export settings and you will be prompted where you want to save the exported contacts file to. This will then export your contacts into a .csv file which can be imported into most mail client software.
I hope this helps.