I went with PNG over SVG because I wanted to keep things unfancy until later given that SVG versions are much bigger than PNG versions and I've heard rumors of

I went with PNG over SVG because I wanted to keep things unfancy until later given that SVG versions are much bigger than PNG versions and I've heard rumors of SVG issues on Mobile Safari. Optional SVG support will likely be added later. Re unnecessary rigging (hogan.js, jquery, backbone), they're there because this hack was original built as part of a larger project. I'll be tearing them out as time allows because they're definitely not needed. Re d3 and approaching problem differently, I wholeheartedly agree. I'll be happy to use a 20 line d3.js version if someone comes up with one. :-)