In a post earlier today I mentioned Gapminder. Gapminder is a great tool for creating data visualizations. Gapminder gives users the ability to create graphs of hundreds of demographic and economic indicators. I like Gapminder because it provides a good way for visual learners to see data sets in a context that is significantly different from standard data sets.
Gapminder has a page for educators on which they can find thematic animations, graphs, quizzes, model lessons, and a PDF guide to using Gapminder. For teachers working in schools with slow Internet connections or very strict filtering, Gapminder has a desktop application that you can download and install for Mac or Windows computers. The video below demonstrates Gapminder desktop.