Right now, we use the jquery sparkines library : http://omnipotent.net/jquery.sparkline/ and some rendered PNGs to show data. The sparklines are JS and render to canvas. All good.

Enter the Google Visualisation library : http://code.google.com/apis/visualization/documentation/gallery.html

Now some of these are totally awesome. One in particular grabs my attention: http://code.google.com/apis/visualization/documentation/gallery/annotatedtimeline.html

However : this annotation requires flash. Do I avoid it for that reason? Should I just query the client to see if they have flash and selectively degrade to an alternative (such as http://danvk.org/dygraphs/)?

So, overall, how evil is Flash in your opinion?