On a pretty regular basis I end up with something on my plate that needs to be done today or tomorrow, and supercedes my other work. GTD has reduced but not elminated these situations. What's the default GTD approach for these things. My guess would be that I run them through the GTD process in miniature, since they're essentially mini projects: process them into my queue, do some organization to figure out what i need to do, crank on the next actions as hard landscape items.