Absolutely! I find that to get anything written I need to unplug. I'm a grad student, and I find that when I sit down to write, there is always one more citation I need to check out before I can write. Unplugging allows me to get my thoughts on paper (or into Onenote at least!) and I can check out the citation afterwards. A friend of mine recommends starting the day unplugged, even if just for an hour, and getting stuck into an important task right away. The task gets done mainly because you focus on it before the barrage of communications via email rss twitter etc. Unplugging definitely helps - but I start to get anxious if I'm unplugged for more than a couple of hours!
I agree completely. I uninstalled all the games from all my machines. I've recently had to stop taking novels for my commute - I swear the call to me from my bag!