Too obvious to be what you are looking for Horace, but it seems to match your requirements in the last post...

Code:
11:23:40 SQL> select * from temp_table1;

  CUST_NUM FAVOURITE_ FAVOURITE_                                 
---------- ---------- ----------                                 
         1 red        porsche                                    
         2 blue       ferrari                                    
         4 orange     Skoda                                      
         6 purple     mini                                       

11:23:47 SQL> select * from temp_table2;

  CUST_NUM FAVOURITE_ FAVOURITE_                                 
---------- ---------- ----------                                 
         1 red        porsche                                    
         3 blue       ferrari                                    
         5 orange     Beetle                                     
         6 red        mini                                       

11:23:52 SQL> select a.*, b.*
11:23:59   2  from temp_table1 a,
11:23:59   3       temp_table2 b
11:23:59   4  where a.cust_num = b.cust_num
11:23:59   5   and (a.favourite_colour<>b.favourite_colour
11:23:59   6   or a.favourite_car<>b.favourite_car);

  CUST_NUM FAVOURITE_ FAVOURITE_   CUST_NUM FAVOURITE_ FAVOURITE_
---------- ---------- ---------- ---------- ---------- ----------
         6 purple     mini                6 red        mini      

11:24:00 SQL> spool off