I was over at the HST forums the other day asking about the Rippetoe squats and here is part of the response I got. The youtube video is not of me but of an example someone else gave and the comments on the video follows.
I tried these squats yesterday and admit my back felt great...just have to remember to put the bar lower on your back. Youtube has a lot of Rippetoe videos.
Also, I can't see the video above, the wonderful IT guy blocked me from youtube so I can't comment on it.
[ame="http://www.youtube.com/watch?v=A6TLa5ICl0Y"]YouTube - Low Bar Squat 147.5kg 5x3[/ame]
Yeah you are definitely wide. That is much more like a powerlifter squat than the Rippetoe squat. The hip drive issue should be fixed if you do some drills with a TUBOW or some other object that you can place infront of your toe that you can touch your knee with when you squat. The knee should stop moving forward (about tip of the knee over the tip of the toe although this can change due to individual morphologies) about 1/3 to 1/2 of the descent and remain in that position for the remainder of the trip down and the equivalent back up. This allows the hamstring to participate as a primary mover. As the weight got heavier this occurred naturally but there was still a bit of knee wobble which can happen with heavy weight, such as your triples. The TUBOW gives a tactile stimulus during the response so you know what your knees are doing without having to look at them or directly concentrate on them.
The powerlifting style squat has a more vertical shin which requires that the hips are back further which requires that that the back be more horizontal which minimizes the use of the quads. You can generally move more weight this way, but the idea of the Rippetoe squat is to become stronger overall. The Rippetoe squat requires more knees forward which gives more balanced load to all the muscle groups of the legs. It is very hard to bring the knees forward over the top of the toes with the wide stance of the powerlifting squat so the Rippetoe squat requires a bit closer of a stance.
On the descent think knees forward and hips backward at the same time. If the knees are over the tips of the toes, the hip are back, the bar is balanced over the middle of the foot, then the back should be at its current angle for the rest of the descent. The shoulders should rise with the hips and vice versa.
Fixing the "looking down" thing should be easy if you stare at a spot on the floor 6-10 feet in front of you. If that does not work then practice squating with a tennis ball held under your chin. This will help you keep your neck in a neutral position.