"What is your greatest weakness?"
This is one of the most DREADED interview questions (well, at least to me it is). When does anyone ever want to intentionally tell someone about their greatest shortcomings are as an individual, or as a professional. Well, the important thing to note here is that your interviewer is not really trying to nit-pick and find out everything bad about you. Instead, what your interviewer is really trying to do is assess how you manage, or make efforts to overcome and improve your weakness.
Check out this VERY informative article that is featured on Best-Job-Interview.com titled Interview Questions Weaknesses. They've got a great chart that lists out various weaknesses, how they can be perceived in the workplace, and how they can be positively managed.