Two color map
Being able to use only two colors on a map might at first seems like a limitation. But it makes things much less cluttered and easier to understand, if you choose the right data to visualize.
This is a map of every building in Manhattan. Each blue bubble is a building, and the size of the bubble is determined by how many floors that building has. The background of the map is white, and the building bubbles are blue. The attribute that gives a meaning to the map layout is the bubble size.
Notice how easy it is to pick out the areas where skyscrapers exist. Better yet, zoom in a bit and the city begins to deconstruct. The space between buildings increases and you can see the relative footprints of a high-rise or a walk-up.
Current event map
I had been interested in the number of Americans who joined/tried to join ISIS after reading a couple articles about them. When we read about historical rebel groups, we tend to ignore the fact that that kind of thing can happen in our present day. At least I do. This was an attempt to humanize some of these people.
Using Odyssey.js I constructed a simple list of people and the places of their origin, along with short blurbs taken from the original article (dutifully cited in the first slide). It shows that potential jihadists can be found all over the country, and some are even that guy who "was a goofball in high school."