While I agree with what most posted, also try to analyze your environment. for example, keyboard, mouse vs trackpad, mouse pad, desk space, what's on your desk, dividers vs open office, 1 or 2 monitors, headphones vs earbuds, window vs white walls, slow music vs techno, noise level, personal problems etc. Really investing time in this can definitely create more hours of productivity, and if not, at least your comfortable :) A coworker of mine, brought in a lazy boy from home to the office, but he ends up really productive.