Best programming chair

Caffeinebot writes: "As a programmer I have a tendency to get engrossed in the current bug/feature/solution, for hours at a time. Even when Gnome imposes a typing break every hour, by the end of the day my back gets sore and my overall body is unhappy- so I ask slashdotters what is your favorite chair that gives you maximum upper and lower lumbar support for maximum ergonomic comfort?"