One of my major productivity boosting strategies while at university was to keep moving quite frequently. Rather than sit in one spot and have my level of attention gradually taper off to almost nothing, I would circulate between libraries, coffee shops, and other places where reading and writing could be undertaken. While the little walking pauses diminished the total time available in which to do work, the loss was more than compensated by better productivity while actually working.
It would be nice if more of the working world incorporated such options, rather than maintaining the expectation that a person will generally stick to their office or cubicle. The latter, in particular, seem well designed to soften the focus of one’s mind. Quite probably, the proliferation of portable computers and wireless communication options will eventually make such peripatetic work styles acceptable in even the stuffiest of environments. Until then, there is nothing for it but to note with appreciation how one’s mind re-awakens with the transition from florescent-lit beige fabric to the high contrast, air-circulating wider world.