I bought a new office chair. My selection process was to take my coat off and sit on every single damn chair in the store until I found which one was the least awful. The most comfortable (at any price) that I found was this one - the multiple points of adjustment turned out to be the key so that I had both enough padding and lower back support. Link
Continuation of: Spend Money on Ergonomics, by Kevin
Three years have elapsed since Kevin wisely told us to spend money on treating our bodies well. It may be time to check for new gadgets, to verify what has worked and what has not etc...
If you have purchased an item for this purpose, or intend to buy one and don't know which, tell here, ask here.
Nick Bostrom uses a mouse that looks like a plane controller joystick.
I've seen keyboards that bend sideways, that are concave, that are convex, and that look like a sphere.
At FHI, dozens of books are used so that computer screens stay at eye level or above.
But I am no expert and I have not looked myself, nor would know how to. So please share in the comments the best knowledge about:
Keyboards
Mice
Chairs
Balls to sit on
Pillows
Beds/Matresses etc..
Screens - Size, position, brightness etc...
Other household office items - Stairs, Handles, Shower etc...