There are a number of articles out there on how to pick a good ergonomic computer chair, but I liked the “office chairs aren’t socks–one size doesn’t fit all” comment in Are You Comfortable with Your Office Chair? It goes into selecting an office chair that fits you and emphasizes why what works for your co-worker won’t work for you. The blurb, borrowed from OfficeMax, suggests adjustable chairs and lets you know all the places your chair should be adjustable (up and down isn’t enough, folks).