The field of HCI known as Considerate Computing or Interruption Management appears to be taking off, shoving its way into widespread consciousness in the form of a New York Times Magazine article “Meet the Life Hackers” and a follow up segment on NPR’s Day to Day (Thanks to Frank)
One can find a slightly deeper overview of the field of considerate computing in here [Warning: PDF] , published January 2005 in Scientific American.
This is a fascinating area of study (for me at least) and its really just in its infancy – computers have finally gotten so powerful that there are lots of left over cycles to make users come first, and taming the information firehose that was enabled by computers in the first place. The foundational studies of just how much interruptions affect users accomplishing their primary task were published in 2002. One study [(McFarlane, 2002) ](http://www.interruptions.net/literature/McFarlane-HCI02_2.pdf) of a set of users playing an interactive game interrupted by a dialog posing simple questions showed a 36% decrease in accurate game play, and 70% decrease in accurately handling the interrupting dialog.
I wrote a paper surveying some of the basic research in the field, as well as focused on managing person-to-person remote-collaboration interruptions in the spring for my HCI (Comp 171) class at Tufts if you’re interested.
The best resource I know of for material in this area is www.interruptions.org which has PDF available of much of the important research in the field, including the two “foundational sources”, one of which I referenced above.