I wish we could do away with the custom of hand shaking.
Not only for the reasons listed above, but also it's a quick way to spread disease.
I remember crying out in pain one time when a co-worker I hadn't seen in a while rushed up to me and energeticly shook my hand. I was in my early 40's then and hadn't had any problems. I wasn't expecting the hand shake so my hand was not "flat" and he crushed my hand. It hurt so bad and he felt bad when I cried out in pain.
And I hope people leave the bear hugs with the bears. A gentle hug is a lot better.