OLYMPUS DIGITAL CAMERA
This is the Darwin stick insect, Eurycnema osiris. [Confirmed by expert in stick insects]. It was very large - at least a handspan in length. We found it on Ubirr Rock in Kakadu National Park.

More information here:
http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:86c07333-2690-4aa2-b667-2605594da07f