Return the uniqueidentifier generated by a default on insert

I think you are looking for output

DECLARE @MyTableVar table([testID] [uniqueidentifier]);
 INSERT [AddressBook] ([address], [zipcode])
        OUTPUT INSERTED.[testID] INTO @MyTableVar
 VALUES (N'address', N'zipcode');

--Display the result set of the table variable.
 SELECT [testID] FROM @MyTableVar;

GO

uniqueidentifier may not be the most efficient id here but this is an answer to the stated question