Nick at 2010-10-07 10:58:25:
I don't see it *quite* the same way. Sure, it's absolutely possible to get some prep-writing done in any one of those non-butt-in-chair environments. You might even get the solid gold idea that puts generations of offspring through college and grad school while you're ordering a bear claw at Intelligentsia.
But I would never *count* on getting anything done away from the desk. Butt-in-chair time is where the rubber meets the road. I'm getting work done, even if that work is just figuring out what's keeping me from getting work done. If I'm doing laundry or shopping at Trader Joe's, chances are I'm going to think about writing at some point, but when I'm in the chair, writing is my true focus -- and that makes a big difference. I don't really count anything else as "writing" time.