Google Charting API

Today, I stumbled on Google's Charting API and it's too cool not to mention. It's URL based, so it's trivial to toss a chart in on page. Here's an example:

To use it, just build up an img URL:

  http://chart.apis.google.com/chart?cht=p3&
      chd=t:10.0,30.0,60.0&
      chs=250x100&
      chl=Neat|Useful|Handy

This should make adding graphs to a web app a truly easy process.