When yesterday the batteries of my wireless mouse died all of a sudden I immediately added a "get batteries" item to my GTD-style to-do list and was rather pleased with myself when that actually led me to buying some today (as opposed to "weeks later" in my old, unorganized existence).

This pride in having a working GTD setup grew even more when I was about to put the remaining new batteries into a designated place (a drawer reserved solely for office supplies) rather than doing it the old way and just shoving them somewhere  - and quickly deflated into self irony when I found a pack of spare batteries that I had bought at the time expressively as an emergency replacement for the mouse and/or keyboard sitting in said drawer... ;-)