Chart Suggestions -- A Thought-Starter

I've noticed some curious charts and graphs in various posts on HN lately. Trend lines where bar charts are required. Pie charts where they aren't applicable. Etc.

I saw this graphic a while back and found it to be quite insightful. I spent a bit of time searching around for it because I think never hurts to have a refresher in the art of conveying information intelligently.

I'm sure I've seen this before, though I'm not sure whether it was on HN.