Russian President Dmitry Medvedev illustrated his call for a supranational currency to replace the dollar by pulling from his pocket a sample coin of a “united future world currency.”“Here it is,” Medvedev told reporters today in L’Aquila, Italy, after a summit of the Group of Eight nations. “You can see it and touch it.” The coin, which bears the words “unity in diversity,” was minted in Belgium and presented to the heads of G-8 delegations, Medvedev said.The question of a supranational currency “concerns everyone now, even the mints,” Medvedev said. The test coin “means they’re getting ready. I think it’s a good sign that we understand how interdependent we are”...