"Tell us about a time where you have influenced a group of people, outside of your employment scenarios and your peer groups".
Yep, if you haven't had an experience of teaching children something, you were pretty much screwed. Competency questions can be utterly fiendish at times!
The other questions which always tripped me up in an interview scenario:
What is your biggest regret?
Tell me about a time that you had to pursued somebody to your view point
When have you taken the initiative to improve a process? What was the result?
How do you fit into a team?
What elements of leadership do you think are the most important?
Outside of your working ability and technical skills, what are your most valuable attributes?
Tell me about a time you made a mistake. How did you rectify the situation?
Tell me about a time you had a confrontation in a employment scenario - what was the result?
What is your single most strong point?
Demonstrate to me, with an example, your time management skills.
Tell me about a time whereby you had to improve your time management skills?
How do you cope with defeat?
What's your biggest fear?
Ewww, evil interviews!