A minute later, a small circle of people from our tour had gathered behind me, watching the snake. Then our guide came over and told us to run. We didn't. We just took a couple of steps back and kept watching, reaching for our cameras before he grabbed a rock and a stick and beat the beast to death. Which took some doing.
Our guide (a top bloke from Red Earth Safari who grew up in the outback and was only happy when we were stuck in the middle of nowhere) told us it was a Mulga snake. Pretty, yet highly venomous with "the largest recorded venom output of any snake," according to this website. There wasn't a house - let alone a hospital - around for miles and had it bitten one of us, we'd have been screwed. It was an excellent start to the evening.
During dinner we were joined by a huntsman spider, which is also (of course) highly lethal, but thankfully it's fangs aren't sharp enough to penetrate adult human skin. Why such small creatures pack enough venom to kill a horse when they only eat insects is beyond me.
After a few songs around the campfire we decided to sleep in the open air. With no light for miles around, the stars were brighter than I'd ever seen before.