The euro is not just giving the dollar a run for its money in international financial circles; even the Mafia has switched over to the euro:

"..When I asked a smaller group of Wall Street bankers the same question, they were more doubtful - though one observed that the euro is already the preferred currency of organised crime because, unlike the Fed, which no longer issues bills with a value above $100, the European Central Bank issues a high-denomination E500 note. That makes it possible to cram around E7m into a briefcase - which can come in useful in some parts of Colombia"