Here's a fun one: the BBC have a quiz online for you to find out your "sex i.d. profile" -- that is, do you have a "male" brain or a "female" one. Let's not get caught up in a discussion of sex differences; just do it because ... well, I don't know, why do we like answering quizzes that purport to tell us something about ourselves? (although really what they generally do is confirm what we already know about ourselves -- and if they don't support our own beliefs we'll see that as proof that they're stupid). Anyway, ignoring the whole male brain/female brain thing, it's got some interesting little tests of your spatial abilities and your degree of empathy and ability to judge other people's emotions, among other things. Bear in mind that many factors impact on your performance, not least of which is practice (I amused myself by retaking the spatial test and significantly improved my score on the 2nd go).