It's amazing how much having a place to write affects how much work you get done. As I mentioned before, my room (which also happens to be my work-space) has undergone some major renovations lately. This past year my `work space' has been the living room sofa. That... turned out not to be the best plan. Our living room gets a lot of traffic. I tried writing on my bed, but that's also where I watch Hulu and read blogs. (Besides, I was giving myself a crink in the neck like you wouldn't believe.)
Now that my room is mostly back together, I've unearthed my favorite chair, and designated it my writing space. I have decreed that if my laptop is open and I'm setting in that chair I am not allowed to be check Facebook, play Mahjong or watch Hulu. If I want to do any of those things, I have to move. It's amazing how much writing I get done now when I'm feeling too lazy to move.
I don't think people have to have a special place in order to write, but if you're the sort of person who needs to give your self-discipline a nudge once in awhile, finding a special writing spot can be a great way to make yourself buckle down to business.