Ed Manley, an urban researcher in the UK, decided to take open data from Winnipeg and make dot density maps. One shows variation in ethnicity, one shows linguistic variation, and another shows income disparity.
As Ed explains on his blog, "These maps are often used to map Census statistics, where single points equate to actual individuals. For each Census area, you generate points for the population in the area – you have 500 people, you generate 500 points – colour the points according to some population indicator, and then distribute them randomly across that area.
There are flaws, of course, it is a bit more artistic than functionally informative, and the random distribution of categorised points within an area doesn’t always make sense, but at small region sizes it generally works well."
Read more about Ed's density mapping process here: http://urbanmovements.co.uk/