one thing that has seemed to impede my progress with GTD is interruptions - phone calls, people dropping by, or even getting caught by coworkers on the way back from the bathroom, etc. some of the time i am able to simply turn off my phone or shut my office door, but other times it is unavoidable. so, for example, i'll set aside a hour for work, and then smack in the middle of that time someone will come bother me for 10-15 minutes or so, and then i'll find i only have 15 minutes left which is usually not enough time for me to finish what i need to have finished. it's maddening, and the end result is that i end up tacking on an hour or two to my work day just to be able to get my work done. anyone have any advice? how do *you* deal with interruptions?