Has anybody done, or thought about, moving your 401K into the Noble Gold?

What are people's opinions on this? I purchased silver last week and await its arrival, but I have a few 401Ks from previous employers and I am still quite young, should i put some, most, or all, of my existing 401Ks into a Precious Metal IRA?

Or would it be wiser to leave my 401K in the stocks/money markets (or whatever they are in)?