Thanks for the tip!Yep. At least in the "geekier" circles, remember, GTD is older than the iPhone.
What helped me for a time was division by hardware.
So I had @keyboard, @mousing, @touchscreen. I also experimented with @offline for things that didn't need an internet connection and @mulitmedia-noise for things that I could do very well while listening to music, podcast or watching videos. And also @silence for things that I wanted to do in the silence of the morning (or late evening.)
Another thing that worked well for me was sorting by recency. So, every new NA would be added on top of the list, thus the first tasks tended to be from projects that were "hot", either brand new or I had worked on them recently.
The slower projects would wander to the bottom of the pile in a somewhat organic manner, to be picked up later at slower times.