I was doing some overdue blog house-keeping today and headed over to the google code page to see what new widgets were available. It saw a link to a chart api. It's pretty good stuff. You can make all the usual charts like pie, bar,scatter and line charts plus venn diagrams.
Here is an example. This image you see below is being generated on the fly, look at the source for yourself if you don't believe me. You can even plug it into your browser and start playing with the parameters for yourself if you are skeptical.
The "code" for that little diagram is amazingly simple.
<img src="http://chart.apis.google.com/chart?chs=400x300&chd=s:Chart Preferences&chdl=People Who Blog|People who Like Charts|People who read my blog&chf=efefef&cht=v&chd=t:1000,250,10,50,7,6,10" />It might look like goobledy-gook to you, but if you head over to the documentation it's pretty simple.
Nice site!