Image - River Wylye, Stoford, Wiltshire (c) Rhys Jones 2008
My Swedish friend, Lina Kvist, has an interesting personality test on her blog 'Famous Last Words' http://oxycay628.blogspot.com/
I used to teach some courses a few years ago where the Carl Jung -Isabel Myers-Briggs testing methodology was used to help determine the profile of students on the course.
If you want to have a go at the test you can do it here - http://www.humanmetrics.com/cgi-win/JTypes2.asp but be as honest as you can otherwise the garbage-in garbage-out rule will apply and you won't get the most accurate assessment.
As with everything the results should be interpreted with a health-warning and ideallly should be reviewed with a trained professional but they do give an insight into the complexities of our personalities. As a photographer it can help get obtain good results to try and understand the personality of the subject as well as you can - and maybe the subject should have an insight into the personality of their photographer since it is a 50-50 partnership!
For the record my personality came out ENFJ -some anlaysis of that here