Rob Mee of Pivotal Labs:
The reality is that most programmers working on their own only spend a small fraction of their day actually programming: the interruptions are legion, and dropping in and out of a state of concentrated focus takes most of their day. There is a solution, however: pair program. Two programmers, one computer. No email, no Twitter, no phone calls (at least not unscheduled; you can take breaks at regular intervals to handle these things). If you do this, what you get is a full day of pure programming. And “getting in the zone” with someone else actually takes almost no time at all. It’s a completely different way of working, and I maintain that it is far more efficient than working alone ever can be. And in fact, with the current level of device-driven distraction in the workplace, I’d suggest it is the only way that software teams can operate at peak efficiency.