This Christmas, the Golden Compass is coming to theatres. If you read my review from a few months back, you'll remember I really liked this set of books. They compare very favorably to the Harry Potter Series and get into some really interesting theological stuff. I've even got Mel hooked – and he rarely reads fiction.
In any case, I won't spoil anything in the movie by saying that, in the world of the Golden Compass, a person's soul lives outside their body in the form of a daemon – an animal spirit that accompanies them through life.
While a young person's daemon is changeable, as a person ages their daemon eventually settles into one form, according to their character and nature. A person's daemon is usually of the opposite sex.
Here's my Daemon
And here's Mel's
You can find your own daemon here.