This is another variation to the previous question. This question is a little better because the question wants you to identify an area you are disorganized. Make sure to emphasize the organized portion of the answer. If you are truly an organized person, then it is really tough thinking about an area you are disorganized. So thinking ahead of time will allow you to make a good impression with a solid answer.
This answer brings a little humor to the question. It lightens the mood and makes a person seem real instead of appearing to be perfect. However, if the job you are applying for requires constant customer interaction, then this answer will not be good. This answer would be better for an office job where not many people will see your desk.