Are there small personal tasks you can handle with a spare few moments?
I carry a planner with me, and include thank you notes/birthday cards/etc. that need writing, plus a list of things like appointments/phone calls I need to make, bills to pay (or set up online payment for) -- basically any errand that can be done at a desk with pen, phone, or computer. I take care of what I can in spare moments during the day. That way the time doesn't get wasted with mindless surfing, and I can then use my non-office time for things like exercising and cooking at home!
You'd be surprised at what you can get done with time that otherwise might get wasted. I'm a lawyer at a large firm (so my time is pretty much literally money), but most days I have at least a few moments where I'm waiting on someone else to do something, etc. in which I can get a few things ticked off the list.
Starting Weight: 260 lbs. (November 2010)
Quasi-Maintenance: 165 lbs. (June 2011)
Goal Weight: 150 lbs. (reached December 8, 2011)
Size 22W to Size 4
Currently maintaining within 5 lbs. (+ or -) of goal. I weigh daily, but also use a tape measure and the fit of my clothes to guage how well I'm doing.