Mike Bostock has created some really great visualizations of sampling, shuffling, sorting, and maze generation algorithms. He ends with a quick discussion of using vision to think, using his NYTimes interactive graphic “Is It Better to Rent or Buy?” as an example:

To fix this, we need to do more than output a single number. We need to show how the underlying system works. The new calculator therefore charts every variable and lets you quickly explore any variable’s effect by adjusting the associated slider.

via Flowing Data