I like things like this too (and have to do some of this kind of stuff for my job). Anyone know Myers-Briggs?
http://www.humanmetrics.com/cgi-win/JTypes2.asp
My all time favourite is Dorothy Rowe's theories of introversion and extraversion (in her book
The Successful Self - unfortunately couldn't find any online test or anything).
Honey and Mumford's learning styles is good too (it's meant to be about how people learn, but I think it says loads more about a person than that).
http://www.campaign-for-learning.org.uk/aboutyourlearning/whatlearning.htm The online test is £10, though!
But hey, seeing as Star Wars has been such a topic of interest this week, how about finding out which Star Wars character you are?! And it's meant to be a legit psychological test....
http://www.outofservice.com/starwars/
Cath
<Added>And the Dorothy Rowe theory
always influences me when creating characters!