As far as I know, the U.S. is the only first-world country that still uses paper currency at such a low value. Canada introduced their one-dollar coin in 1987 and retired their paper dollar; in 1996 they killed their two-dollar bill and replaced it with a two-dollar coin. Great Britain began circulating a one-pound coin in 1983 and withdrew their one-pound note several years later. Europe has had one-Euro and two-Euro coins since inception of the currency; they never printed one-Euro or two-Euro notes. Japan's 100-yen coin dates back to 1967 (!!), and they added a 500-yen coin in 1982 although they have had problems with counterfeits. The Swiss changed to one-franc, two-franc, and five-franc coins in 1995.
Alas, the U.S. hasn't seen the light. We have had silver dollars, Eisenhower dollars, Anthony dollars, Sacagawea dollars, and now presidential dollars. Until and unless the paper dollar is withdrawn, however, the dollar coin will never take off. Ending the paper dollar would save money; it is opposed by suppliers of paper, ink, printing presses, and labor (i.e. employees) to the Bureau of Engraving and Printing.
I find that the Sacagawea and presidential dollar coins are very handy. It's easy to distinguish them in my pocket from quarters, and I like the convenience of keeping a few in my automobile ashtray.
In the meantime, if you want to take individual action in this regard -- other than writing your congressman and senators -- you can order 250 one-dollar coins directly from the U.S. Mint for $250 using a credit card. The Mint pays shipping cost to your residence. The more people who do this, the more circulation of these coins there will be. The link is http://www.usmint.gov/mint_programs/$1coin/?action=directShip.
