Interesting article. As mentioned above, I'm not sure that just generating ideas is the same as generating good ideas. And when it all boils down to getting things done (GTD), I really have to pay attention. If I'm in a creative mood, and I don't have time schedules looming over my shoulder, then sure, it's okay to let the mind wander.

I'll also mention that I've recently gotten into Pomodoro, and that has really helped me to pay attention. I never would have thought so, but I'm actually able to code and be a lot more efficient in my Internet usage using the technique.