I really can’t emphasize enough the importance of a really comfortable chair.
I just got a “new desk chair”:http://www.steelcase.com/servlet/ProductServlet?ACTION=4&CAT_ID=9&CAT_NAME=Seating&TYPE_ID=23&TYPE_NAME=High+Performance&LINE_ID=259 at work which is super-duper adjustable and actually fits my body. After a full day of work, I still felt totally comfortable sitting in it, not hunched or slouched or cramped. Now if I could just move my mouse in a little closer (say, right where the numpad is), then I’d be in heaven. (so to speak.)
Now the chair I have at home is looking even crummier, alas. (Why is it so hard to find out how much it’d cost for me to get myself one of these?!)