Tom from Stamen Design and Hadley from the GGobi group kindly pointed me to the recently ported Flare visualization toolkit. Developed by Berkeley's Jeffrey Heer, Flare looks extremely useful for anyone who is interested in developing interactive visualizations (e.g. time series, stacked bar, pie charts, graph) for the Web that run in the Adobe Flash player.
There's a pretty good tutorial that I, as a beginner, found straightforward. I ran into some problems when I was trying to "import a library into another project," but per Jeffrey's suggestion, I upgraded to Adobe Flex 3 beta (currently a free download). That cured my problems. Adobe Flex is apparently still a little rough around the edges. Oh right, and the tutorial provides instructions on how to develop with Flare in the Flex Builder environment.
I'm currently going through the demos to gain a better understanding of both Flare and Actionscript, and it looks very promising. I'm pretty excited about what I can do once I've improved my Actionscript programming skills.
Check out some screenshots from the Flare demo reel after the jump.