I have a really pesky power steering fluid leak on the drivers side of the motor--its spraying fluid all over the underside of the car, underbody-- and I don't know much about the power steering system. I know its probably one of the lines running to the knuckle/steering gear.

Any common culprit here? Where should I start with this? I've already spent an hour underneath the thing wiping down lines and hunting for a leak, but nothing.