[jfoutz]

For model rockets at least, if the center of pressure is lower than the center of gravity, lift from the fins will straighten up the rocket. it can be confusing because the lift is pushing sideways (aligned with the fin) rather than up. Probably doesn't matter at all for a Saturn 5.

[mikenew]

Fins provide drag which moves the center of drag behind the center of gravity. I guess they could provide lift to spin the rocket, but I don't think I've ever seen that on a model that works that way.