[barbazoo]

This reminds me of my grandma who claimed she could tell if a Kinder Surprise egg had a plastic toy or one of the, often more desired, figurines in it by shaking it a certain way. That always impressed me. I wonder if that's why she did it or if it was to amuse me. I miss my grandma.

[throwaway894345]

In general, it's easier to approximate a difference in the weight of two objects by shaking them rather than merely holding them in either hand.