Brad Feld wrote an excellent post, What's A Vacation?
He lists 5 strategies that one can use to isolate himself/herself from the world to get some piece of mind. I also found myself more and more often in this state when I feel there's too much going on and I have to focus. When this happens I set Piding (ICQ, Google Chat, MSN), Skype and Evolution to offline mode, shut down my cellphone and just focus on the task ahead. It works pretty effectively.
I plan to schedule more activities (that most normal people do) on a regular basis to cut myself from the cyberspace and socialize more often. I've recently had a PRK eye surgery which limits me in some activites for a while, but there's still lots of things to do.