We originally weren't going to put an office in our new house, given we don't really use our current one. But I saw this idea in Home Beautiful (it is actually another part of the lounge I blogged about last week).
I love how the cupboards and drawers i the office match in with the rest of the house.
And I love how they have used the space behind the kitchen. I can see ours having a frosted glass door at the end, and a long narrow window above the desk.