Here are some suggestions.
The IIS AstroCamp 18-21 January 2007
http://www.iceinspace.com.au/index.php?iisac
70km NW of Newcastle, bunk beds available.
The South Pacific Star Party: 13 - 15 April, 2007
http://www.asnsw.com/spsp/spsp.htm
160km NW of Sydney, bring a tent.
The Queensland Astrofest 6-12 August 2007
http://www.qldastrofest.org.au/
100km NW of Brisbane, bunk beds available.
Here is a list of other places
http://www.quasarastronomy.com.au/places.htm