From a TEDxMidwest talk given by Jason Fried of 37 Signals:

Why work doesn’t happen at work

We’ve all heard of the casual Friday thing. I don’t know if people still do that. But how about no-talk Thursdays. How about — pick one Thursday just once a month and cut that day in half and just say the afternoon — I’ll make it really easy for you. So just the afternoon, one Thursday. The first Thursday of the month — just the afternoon — nobody in the office can talk to each other. Just silence, that’s it. And what you’ll find is that a tremendous amount of work actually gets done when nobody talks to each other. This is when people actually get stuff done, is when no one’s bothering them, when no one’s interrupting them.

And you can give someone — giving someone four hours of uninterrupted time is the best gift you can give anybody at work. It’s better than a computer. It’s better than a new monitor. It’s better than new software, or whatever people typically use. Giving them four hours of quiet time at the office is going to be incredibly valuable. And if you try that, I think you’ll find that you agree. And maybe, hopefully you can do it more often. So maybe it’s every other week, or every week, once a week, afternoons no one can talk to each other. That’s something that you’ll find will really, really work.

Another thing you an try is switching from active communication and collaboration, which is like face-to-face stuff, tapping people on the shoulder, saying hi to them, having meetings, and replace that with more passive models of communication using things like email and instant messaging, or collaboration products — things like that. Now some people might say email is really distracting and I.M. is really distracting, and these other things are really distracting, but they’re distracting at a time of your own choice and your own choosing. You can quit the email app, you can’t quit your boss. You can quit I.M., you can’t hide your manager. You can put these things away, and then you can be interrupted on your own schedule, at your own time, when you’re available, when you’re ready to go again.