As you may or may not know we bought a travel trailer this year (yeah, okay, I've been mentioning it lots). Anyway, so I've been reading lots about trailer towing, trying to learn more so I'm a better driver. And I came across this:
http://www.e-z.net/~ts/ts/JACK.HTM
It shows the difference between jack-knifing and just swinging your trailer out, and why there really is a difference. Kinda cool, I thought.