There are, of course, several Bioinformatics Interest Groups in Australia. Our BIG is based in the University of Sydney and has around 75 members since it was first formed in early 2005. If you want to contact BIG you can e-mail the list at bioinformatics-at-it.usyd.edu.au, or if you would like to be added to the list please contact me directly.
I run the Eden group, which is about one-half of the larger Advanced Networks Research Group.
The newly formed Plant-Animal Interactions Network is a loose collection of researchers interested in the way in which different creatures interact, not just plants and animals, but why spoil a good acronym? My ecological modelling work fits in with this.