Thank you Scott, for the kind words. I often get asked if I am angry because I dont smile much. I tend to have a serious expression on my face as the default position.

How do you even pick up a 100lb rock
Treat it like a clean and jerk. Squat down in a good position, get a grip on the rock, then hike it to your chest and start standing. Use your momentum from standing to assist as you jerk it over your head.

For the throwing, two main styles are used. I prefer the overhead, where the rock is held up over head like an army press. Run forward gathering all the speed you can, then just before the trig (the trig is the board that marks the front line. If you pass it you fault on the throw) jump to a stop and use that 'pop' to help you throw the weight forward.

The other way it is usually thrown is from the chest, pushed off by the strength of the arms. I dont like this myself, since your arms generally are not strong enough to accelerate the rock very fast, not throw it very high. For a smaller rock this style might be better, but with a rock this big height helps.

For every foot it has to fall, it can travel another foot and a half futher. If it is over my head the rock starts out at around 7+ feet. If its on my chest it only has 5+ feet before it falls to earth.

Its a big fricken rock too. I'd say about 18 x 15 x 10 all around, sort of a flattened egg shape, as Scott mentioned.