A heat map is one of the great innovations of visual communication. In an instant, you can spot a weather formation and judge the seriousness of the storm or see the heaviest concentrations of U.S. Internet outages.
We're already inundated with too much information — Twitter feeds, status updates, email archives, etc. — but a heat map represents a good way for upper level management to see problems and successes instantly. The heat maps featured here communicate massive data sets in a way that few images can accomplish.
John Brandon is a former IT manager at a Fortune 100 company who now writes about technology. He has written more than 2,500 articles in the past 10 years. You can follow him on Twitter @jmbrandonbb.