Many of the features you've requested via Google Chart API forum are now live in the Google Chart API:

  • Easily create Sparklines (&cht=ls) without having to manipulate other kinds of graphs.

    sparkline

  • Support for Radar charts (&cht=r or &cht=rs) to display data in a polar coordinate system.

    radar chart

  • A new Map chart type (&cht=t) which makes it easy to colour countries and regions according to your data.

    thematic map of europe


Some other changes we've made:
  • Added scaling for text encoded data
  • Added support for negative numbers on bar charts
  • Added ability to draw data lines on bar charts

You can read more about all of this -- plus the fact that we've lifted the 50,000 queries per day limit -- on the Chart API site. And special thanks to our Technical Writer Lesley Burr, who put together this documentation in her 20% time.