Big, hot and dry. My recommendation is to only visit in the winter!
The outback covers most of South Australia and I've only seen a small part of it.
Not sure why people say there's no water out here - I saw lots of lakes. Only people don't call them lakes, they use another name - 'mirages' or something like that. Doesn't really matter what they're called, as long as they have water in them. They were always in the distance, though - I never got close enough to get a photo . . .
Willie-willies seem to be common out here. I'd often see them doing their little dance along the road or just off it.