Goulburn River National Park, New South Wales -- on low sandstone ridge above the Spring Gully Camping Area. The red colour of the bark is not a standard feature of the species, but is probably some sort of alga. The same coloring is seen on electricity poles, wooden houses and sandstone cliffs in some of the hill regions of NSW. [added Jul 2011] Now I have at last found a reference to the genus of algae that give rise to the red/orange coloring. In Tim Entwisle's blog at talkingplants.blogspot.com/2010_11_01_archive.html
Tim (a specialist in freshwater algae) mentions the group of algae that color tree bark and rocks. It's Trentepohlia
, order Trentepohliales, phylum Chlorophyceae (see Wikipedia). So it's in truth a green alga, though the green chloroplasts are masked by orange pigments.