Great idea. I used to have the GTD workflow map stuck to the wall near my desk. But I heard David talk about how those items that are permanently there become invisible to us day after day after day. I found that to be true. So I like the idea of a changing wallpaper to make it more random (almost tickler like).I'd love an elegant and simple set of mobile wallpapers for the various topics: system outline (1. capture, 2. clarify,...), clarify flow chart, horizons of focus, natural planning model, etc. It would be a nice reminder to have it on my phone lockscreen (which does allow for a slideshow of several wallpapers on my device, so I could add them all).