Net Magazine, By Brian Suda, September 17, 2012
In this article, I want to introduce you to 20 different tools for creating visualisations: from simple charts to complex graphs, maps and infographics. Almost everything here is available for free, and some you have probably installed already.
... Online visualisations
3. Google Chart API
However, the API has just about everything but the kitchen sink, from bar charts and line graphs to maps and even QR codes. You will probably find the right visualisation for your needs as long as you are comfortable with the Google look and not in need of extreme customisation
Flot is a great library for line graphs and bar charts. It works in all browsers that support canvas - which means most of the popular ones, with some extra libraries to get canvas to work as VML in older browsers. It's a jQuery library, so if you're already familiar with jQuery, it's easy to manipulate the calls back, styling and behaviour of the graphics.
If you are in need of an infographic rather than a data visualisation, there is a new crop of tools out there to help. Visual.ly is probably the most popular of these. Although primarily an online marketplace for infographic designers, its Create option lets you pick a template, connect it to your Facebook or Twitter account and get some nice cartoon graphics back. While the results are currently limited, it's a useful source of inspiration - both good and bad - and a site I expect to see grow in future, accepting more formats and creating more interesting graphics.