Slightly old news, but anyway …
These were originally made famous by Hans Rosling. If you haven’t seen his TED talks please start here:
This seems like a solution itching for a good problem.
These charts can easily handle five dimensions of data: x-axis, y-axis, bubble size and bubble colour + time scale.
Does anybody have an interesting and available data set like that which we could all use to play with?
Bonus points for NZ data. :-)