Hello! Me and my wife, both Australian citizens, we like to know if we need China and H.K. Visas?

The last time we visited Honk Kong for 4 days and Guangzhou for 3 days on 14 to 21 July, 2001, for holiday. We will be on a Cruise in March 2013. Our cruise ship will anchor in Shanghai and Honkong for apx. one day, in each port Please, advise us what we need to do. Kind regards, Ned.