Came across this stuff on ebay, it's gone past my price, but someone here might be interested.

Davco "Sound Zero" Soundproofing Membrane Peel & Stick - eBay, Other Building Materials, Building Materials, DIY, Home. (end time 17-Mar-08 10:04:29 AEDST)

and the website for the details -

Davco Construction Materials: Australia

I might even be able to pick it up, of course the roll might get a little shorter on the way home.

Cheers
Simon