Depends on the thinking. For songwriting, it's driving for me, but it requires certain preconditions: route I know well; route that's easy (motorway or major road) so no major concentration needed for corners and junctions; and radio playing something a bit more "edgy" to trip ideas off (Zane Lowe show on Radio 1 is often good, but basically anything except mass-market pop). I always drive with a pen and pad of paper, and/or an MP3 recorder.

For the kind of thinking that's involved in working through something methodically, I just sit down at a computer with a word processor and go.

Graham.