d3js

Also known as waffle charts. Using animated transitions between values, you can allow for comparisons between categories.

Add interaction so that you can show different segments of the data and allow comparisons.

The histogram is my favorite chart type, but it's unintuitive for many. So I've been using the less accurate but less abstract beeswarm.

When there are too many options or categories, it can be helpful to make the data searchable.

Use a force-directed graph to form a collection of bubbles and move them around based on data.

Here are some tips to get you started, based on my own experiences with R, and more recently, the JavaScript library d3.js.

Stacked area charts let you see categorical data over time. Interaction allows you to focus on specific categories without losing sight of the big picture.

Provide a slider for the standard bar chart so that users can shift focus to a point of interest.

Let readers focus on the regions they care about to make their own comparisons and conclusions.