I remember seeing an apartment building in Sydney's eastern suburbs on the TV news. It was made of rendered foam and was being picked to pieces by cockatoos.
This mob
http://www.qt-sys.com.au/index.php/products/ecoseries
have a cladding made of a blend of cement and recycled polystyrene. I have no personal knowledge of them though - they are linked to from Storybook Cottages (a kit home supplier).
If you go with any system, make sure it has been around for a while. If the product is no good, it won't last. You also want to check it has been used in your area and preferably get it installed by people who specialize in it.