You should check out Wotif which is highly recommended by many (including myself). It generally has cheaper prices than normal hotel prices, however, its always best to just compare with the individual hotel's own website, as sometimes they might have some special deals going on. When I searched for Cairns, Port Douglas and Cape Tribulation (<- not as many hotels for Cape Tribulation as the other two though!), a whole list of hotels came up. I haven't yet checked out what is available on
PRICELINE and
HOTWIRE, but, Wotif is certainly a good site for accommodation throughout Australia (and various countries around the world).