Painless Chairs?

Tarrek asks: "Eight or more hours of sitting and slouching with my feet propped up in an uncomfortable, half broken computer chair every single day for years has begun to take it's toll on my back, and I'm still quite young. I was wondering if the slashdot community might have any ideas with regards to a new chair, or just types and designs of chairs, that might be a little kinder to my back, as well as being comfortable enough to sit properly in for an extended period of time?" This is a revisit to a question from two years ago. That was then, what does the picture look like, now?