it depends on the resume, the industry and the postion/role you seek
If you have a section on your specific skills or techniques or methods for productivity or applications of technology that you are facile with you might want to include it. If you have any form of certification or course completion, or you have a "professional growth and development" section or place where you list continuing education perhaps that would be a good place. I think it pays to include anything that is important to you because if the hiring person finds it interesting and important, you have the chance of a match. However, people come with all sorts of prejudices and judgments as well. Maybe, the wiser course is to indicate that you are invested in learning and honing skills in productivity and work flow management. One concern that I have, is that if someone does not know what GTD is or has failed with it, and he or she is not the wonderful supervisor or manager who enjosy learning from their "reports" , you might end up with rejection or friction.