Gold and silver aren't really producing assets--they don't pay interest or dividends, and they don't really go up in value. (They may go up in price when market fluctuations let you buy them at an unusually low price and as inflation makes the money worth less, but that's just the value remaining stable.)

That stability makes gold and silver good stores of value, as long as you don't buy them at historically high prices. If you bought gold six or eight years ago you're sitting pretty right now. It's not so clear that buying gold at today's prices will turn out to be a win.

Besides a store of value, they may also be good in times of great emergency, if things get bad enough that people lose their confidence in cash. In practice, though, the dollar has turned out to be a lot more useful than gold or silver so far, at least in developed countries, even during emergencies, for as long as I've been paying attention.

Having said all that, I've got some gold and silver in my safe deposit box at the bank. I figure it's a hedge against worse emergencies than we've faced so far. Plus, it's pretty.