There's a wonderful little article at the Globe and Mail (Why online should be off limits in the bedroom) about how laptops should be kept out of the bed. The article talks about some more personal reasons why not using your laptop in the bedroom is a good idea, but frankly I think there are some more sensible reasons.

First up, I think it's rude. Reading is a comparatively silent activity, and generally non-intrusive, but using a laptop is far from silent, and there's always the temptation to download a movie or watch a video short. Your partner may want to sleep and using a notebook is probably not going to help.