For various reasons, I've been reading up a bit lately on personality types (you know, Myers-Briggs and all that). Several years ago I took the Keirsey test and came out definitely NFP (iNtuitive Feeling Perceiving as opposed to Sensory Thinking Judging), and borderline on the Introverted/Extraverted dimension. I think I'm probably by nature introverted -- even into my early twenties I was painfully shy -- but that I've learned over time to become more extraverted. In any case I've found some good descriptions of both the INFP (1 | 2 | 3) and ENFP (1 | 2 | 3) personality types, in which I can definitely see aspects of myself.
With regard to their work, INFPs tend to most enjoy a career that is not just a job but a passion or crusade, and I definitely bring that to my work with Jabber (that's one reason people call me the "patron saint" of Jabber, I suppose, since I bring an almost evangelical fervor to the technology). And ENFPs tend not to be detail-oriented and to have a hard time finishing projects, which unfortunately I must admit is true of me. ENFPs also tend to have good diplomatic skills and often are able to translate technical ideas into plain English (and vice-versa), which are strengths of mine. INFPs often express themselves best through writing, and supposedly most of the world's great writers have been INFPs. Not that I'm a great writer, but writing does come easily to me and it's one of the things I do best. So I see a lot of *NFP in me, for better or for worse. :)