Michael-
I read your blog right after I had just finished perusing my task lists for "easy pickins." I was never too interested in productivity and deep organization, but I was attracted to systems and paradigms, which is why GTD caught my attention. But one thing I did do was heavy prioritization of my to-do lists. Not only did I use letters and numbers (A1, B1, C2, etc), I colored them red, yellow and green as yet one more level of prioritization. So, my need to be told what to work on (even when it is me telling me via prioritization) has been difficult to let go of and/or incorporate into GTD. I cannot resist giving due dates to every project, even if the due dates I assign are not intrinsic to the project, just so they’ll line up in some order for my eyeballs.
I think your idea will help, if I can keep from numbering and coloring them once I tag them for placement on “!Today.”