I am not, thank goodness, one of those writers who needs absolute silence and several hours of uninterrupted concentration in order to get anything useful written. But I find that, unless I'm really inspired, I won't just launch into writing a story in an available ten-minute interval. I want to be able to sit down and see some time stretching out before me, and unhurriedly start writing. Half an hour is usually enough time for me to feel mildly producive. Ten minutes isn't enough time for me to even psyche myself up to doing some writing. I look at the clock and think, "By the time I'm mentally prepared for this, I'll have to go back to work."
I don't know if that's really true or not, though. When I was inspired by Silver Scales, I used to jot down three or four paragraphs in that ten or fifteen minute interval. It's almost like there's some Can't-Do force standing between me and my muse, telling me "Don't bother, don't try, don't even think about it." Hmph.
Back to work.