I'm also an INFP. I myself am fascinated by these types. I've taken the test every few years for about the last 10 years. Always the same letters. Much more accurate indicators than say astrological signs, don't you think?
I am a:
very expressed introvert (100%)
moderately expressed intuitive personality (25%)
moderately expressed feeling personality (25%)
slightly expressed perceiving personality (11%)
I'm a little surprised by the percentages. I thought I was becomming less introverted over the years. I sometimes get cabin fever: even though I enjoy being by myself, I like to go out among the people sometimes. But then I quickly tire of them. I don't maintain friendships very well, since they aren't a necessity to me at the core. I think it is essential for the planning profession to have a good mix of the latter three variables in its staffing. Both sides of each can be valuable depending on the situation.
These were from the INFP analysis:
"Some INFPs have a gift for taking technical information and putting it into layman's terms."
"As INTPs tend to have a sense of failed competence, INFPs struggle with the issue of their own ethical perfection, e.g., performance of duty for the greater cause. "