Isn’t it cool! This is Jonathan Aquino’s version of Aeron Ergonomic Chair:
All you need are a regular chair, a telephone book, a cutting board, a towel, and a bungee cord (or belt) – you too can taste the great lower-back support:
… The height can be adjusted by simply adding or removing books from the base of the seat. I first used a telephone book, but I am finding that old encyclopedias provide more finely grained control and a wider base…
Ingenious invention!
Do-It-Yourself Aeron Ergonomic Chair – [Jonathan Aquino’s Mental Garden via Make: Blog]