Immunizations?
 

Traveling to Australia and New Zealand for three weeks; though no immunizations are required but are there any immunizations that are RECOMMENDED?

Well yes actually. I would get immunized against you not wanting to go back home. Many people do this and are quite ok but those who don't spend the rest of the lives wanting to come back and stay here.

Yes, Lizzy, I was infected on my first visit and just have to keep going back.
But seriously, Kris, no special immunizations are needed or recommended. (Of course, I assume you are up-to-date on your regular immunizations anyway.)

Malaria, cholera, typhoid - and don't forget the rabies.

No - just joking.

PS - what immunizations are RECOMMENDED for the US?

Are you travelling in winter? The only immunisation that I can think of (and which I have had) is influenza. It won't stop you getting a cold but protects against certain strains of the flu.