So that's the same as squatting? In the UK I beleive it is 14 years, but all you need to do is live there and have evidence. In addition to that it can take a long time to be evicted.
Did I read that wrong or is it 2 years in Arizona? A person could make a decent living out of that, just living in disused places in Arizona for 2 years (there's surely not a shortage) and then selling them on.