At my last company the phone system had the habit of dying intermittently. I noticed everyone in my department seemed to get a lot more done on days it had died.

I implemented a policy of "no phones" at least 1 hour per day for each person in the department. That means no incoming, and no outgoing. During these times, if someone called, the individual was "in a meeting" and a message was taken unless it was a critical family emergency.

It is amazing how much more you can get done when you know you won't be interrupted.

I have also found an 11:30 lunch has served me well. I can get into someplace, eat, and get back out before the noon crowd hits. The other 1/2 hour I spend sleeping and/or listening to music. Usually in my car, but sometimes in my office depending on weather. Personally, my brain works a whole lot better in the afternoon this way.