I feel MUCH more connected to the money I am spending when I write out paper checks vs e.g. quicken. So for GTD I have used an electronic program (which one has varied) where I can change things easily and print it out in the evening and keep the printouts in a binder which I take with me during the day. One week in 5 I work a totally different work schedule so I also have a LARGE month at a glance calendar.