Stumbled across an interesting page entry at Wikipedia the other day, concerning the Myers-Briggs Type Indicator. I've always been fascinated with psych tests, so I followed a link to a site that has an unauthorized test so I could see which type I fall into.
Going by my results, my type is INTP. Breaking this down, the letters stand for Introversion; iNtuition; Thinking; and, Perceiving.
According to Wiki, this type only makes up 3.3% of the US population. Cool.
Link to the Wikipedia entry on the MBTI.
Link to an MBTI test.
Link to an INTP Profile.