How do you handle distraction, both personally and corporately?

At the corporate level, I've heard of companies that try to channel distraction creatively, allowing workers to allocate a slice of time each week to other pursuits. I expect there are rules regarding what's an appropriate "other pursuit" in the those situations.

At my office my manager gets quite concerned when he thinks I'm, as he calls it, "spinning my wheels." Granted, if I'm on Facebook, reading Order of the Stick or reading Girl Genius then that's easily identifiable as inappropriate-for-workplace activity. But is Exercism? (I learned how to do Linq through Exercism's C# track and it's been really useful.) Or researching for HOPL? Or completing RosettaCode challenges?

Maybe I'm just looking for justifications for corporate misbehaviour, but how to do you keep yourself on target? Okay, I can get really intense sometimes and lose touch with the outside world. And sometimes I wish I could reach into my head and flick the intensity switch on because I'm just not excited at all about the task at hand and would rather be elsewhere.