Google today released a new API called the Chart API, which can be used to generate, well, charts and graphs. Unlike other Google APIs, I think this is easier for the general audience - after all, it just generate a chart and return in (PNG) image format which you can embed in your web page using the simple img tag. The above chart was created by calling:

http://chart.apis.google.com/chart
?cht=p
&chd=t:4,2,1
&chs=400x140
&chl=Haochi ate this slice|For you|For my snow man

Where cht=p tells the API to return the chart in pie chart format, cht=t:4,2,1 represents the values of the chart, chs=400x140 is the size of the chart in pixels, and chl=Haochi ate this slice ... snow man is the labels to the values sated previously.

Of course, this is only a simple demo on what the API can do. You can created line graph, bar graph, venn diagram, and pie charts and specific difference sizes, colors and labels for them with the API.

There are some restrictions on using this API: a limit of 50,000 queries per “user” (supposedly per domain, but it’s unclear) during a 24-hour period and that the charts cannot have a area of greater than 300,000 pixels with the maximum for height or width of 1000 pixels.

Google should build a tool, like Create a Graph, to simplify the process of creating these charts, especially those with a lot of data (well, people should use something else then, but I am just saying). If you are interested on using, or building applications with the Chart API, you can learn more about it on its website.