Owning gold and silver is more about protecting value than "investing" in the traditional sense. That said, both investing and protecting are less about IF you're right, and more about WHEN you're right. Fundamentally (and this is an oversimplification) both silver and gold can represent fantastic wealth preservation methods in an inflationary environment, which is what we are in right now (US government supplied inflation figures are laughable). I wouldn't be surprised to see gold hit $2500/oz in 2012, and Silver hit $75/oz. Silver is more volatile, so if you're into regular trading some money can be made (and lost) with silver ETFs.
If you suspect that a collapse of western monetary systems and their fiat currencies is imminent, (I don't) then silver coin is probably your best bet. Otherwise, ETFs are very simple and inexpensive.