This is going to be a longgggg thread, so I'll keep it short.

My college roommate was a very talented skater and I went out to hang out with him and his crew while they were filming. He must have fallen 20+ times that night, hard. I started to notice that when he would fall he would hit the ground and instantly go into a roll, not landing on his shoulder but falling in a rolling manner that would start on his arm and roll up and over his shoulder and then his back. He'd pop back up on his feet like nothing happened. So this "falling correctly" is more about just rolling and letting the energy produced by your inertia slow down rather than just break on impact. They teach this in martial arts when you have to fall as well.

In sports where there is constant falling like skateboarding, bmx/street, martial arts etc you can learn this from pure repetition as well as knowing that the crash is possibly coming. The problem for this with me is that road cyclists fall a handful of times a year in most cases. I raced every weekend most of the season for two years and only had about 3 or 4 crashes. This is hardly enough time to learn how to "properly" fall, not to mention we're coming from being clipped into bikes at very high rates of speed with an often times totally unexpected emergency. So personally, I don't put too much weight in how to fall outside of the free-ride/gravity/bmx/trick side of our sport. If you can eat it on a road or mtn bike and make the conscious decision to hit the ground and roll properly great, but I don't worry about it.

So, long story short it's hit the ground and transfer the energy, don't land on your hands and try to absorb the energy, but I think most of us have a pretty small chance of accomplishing it. IMHO