http://www.ehow.com/how_4871491_silver-coins-circulation.html
Apparently it is still possible to find silver coins if you are lucky. A friend of mine went to the states last year and brought me back some dimes and I found a 40% silver one (I suspect he may have put it in there for me to find though) I live in Australia and our coins are getting pretty close to face value in copper nickel. It will be interesting to see what happens. When Australia went off British coins (1966) we got a 1/3 oz 50% silver 50c coin in circulation but it was over face value within a year and got replaced immediately but it can still be found.
I purchased this one off amazon earlier this year. It was recommended to me by someone else in the community and I've been quite pleased with it.
I have to point out that Ron Paul is a student of the Austrian School of Economics, mentioned at the 14 minute mark. Economics in One Lesson by Henry Hazlitt * is a great introduction to the Austrian School.