I need to contact Wendy Day (preferable via email), the Australian
publicist of Nicole Kidman and Russell Crowe, but I wasn't able to
find her email address or phone number somewhere.

mario0815 -- 

The closest I have been able to come is the pubished business email
address of Wendy Day's journalist husband, Mark Day.  According to a
recent column in "The Australian," it is mday@ozemail.com.au :

http://www.theaustralian.news.com.au/common/story_page/0,5744,12704710%255E12280,00.html

I hope that another researcher can get you directly to Ms. Day, but,
if that doesn't happen, you might try this address and see if it pans
out for you.  If it does, let me know, and I will post the information
as an "official" answer.

markj-ga