A study just out suggests that subjecting your body to a regimen of periods of vibration will slow bone aging, which takes the form of softening or porosity. Sources for this therapy cover the gamut from riding a Harley-Davidson to holding a purring cat in your lap.
I favor the motorcycle version myself, having subjected myself to this sort of vibration since I was 17 or so, I can attest that the bones in my head are as solid as ever.
A well-sheltered scientist does this sort of experiment by vibrating mice periodically, and comparing them to non-vibrated ones. Shaken vs stirred. An enterprising doctoral candidate could take this up a notch by offering the denizens of a biker bar a coupon good for a free beer in return for a quick bone density test.