Well there have been lots of new drawing machines doing the rounds lately, there's a real thirst to see devices that leap out of the virtual into the
physical. For me, it's all too easy to produce digital things which are interesting - programming or mash-ups or virtual experiments are devalued because they are intangible, you can run a hundred, a thousand, a million variations in a day - it's the proverbial roomful of monkeys with typewriters. The output becomes disposable, it get's hard to see the value, the craft.
So 3D printers and other desktop manufacturing tools and technologies (laser cutters etc) have got more and more popular, it's hard to overestimate how much hunger there is for a tangible, physical, touchable, smellable product of all this clever-clever digital work.
So this isn't wholly original, check out this prior art for more inspiration:
Hektor - the daddy of all hanging drawing machines
Der Kritzler - the smartest one yet
AS220 Drawbot - the basis for mine
SADBot - Instructable for an automatic drawing machine on the same pattern by Dustyn Roberts
But this is the original Polargraph! The term is a portmanteau word invented for this instructable, and it has caught on. People who don't know their drawbot history often use the word to describe any hanging-v plotter, but it is actually means something very specific: A machine that runs the Polargraph software.
Mostly based on the success of this instructable, I started a little workshop making Polargraph parts, and the next-generation Polargraph gear (PolargraphSD). Couple of links below:
Polargraph wiki and code