Great podcast! I just read a story elsewhere about a disheartening study on the time it takes to get re-oriented on a task after an interruption during the weekday. Self-inflicted interruptions by multi-taskers are no better, I'm sure.

In terms of actually attempting to do more than one thing, I'm definitely in the "single-tasking" camp, but I wonder what you (Merlin) and the other commenters think of dividing one's attention during rote activities--obvious ones like listening to talk or music while driving or exercising, or listening to, watching, or reading something while doing mundane, repetitive chores (i.e., having the TV on while doing dishes, or reading e-mail while pulling staples and restacking a mass of paperwork for scanning--something I did quite a bit of back in my desk-jockey days). It seems to me sometimes it's okay to slow productivity down a little, if it allows even the less-deep consumption of content one wouldn't have had time to read/watch/listen to otherwise.

The one that irks me, and that it should by now be obvious can't actually be done, is the people who attempt to have two conversations at once. Anybody who's ever been on the phone with someone who was checking their e-mail knows darn well you certainly--and obviously--can't hold two conversations at once within an order of magnitude of the skill you can hold one.