One number in isolation has to be treated with care, but this, via the Daily Telegraph, is worth watching:

08.20 Another major upset is the news that Greeks are pulling their euros from the country’s banks, afraid of their savings being rapidly devalued if the country does leave the single currency.
Central bank head George Provopoulos told President Karolos Papoulias that savers withdrew at least €700m on Monday.
“Mr Provopoulos told me there was no panic, but there was great fear that could develop into a panic,” the minutes of a meeting with political party leaders quote the president as saying.
“Withdrawals and outflows by 4:00 pm when I called him exceeded €600m and reached €700m,” the President said. “He expects total outflows of about €800m.”
There are no signs of a full-on run on the banks yet, no queues outside banks in Athens or anything like that, but the situation is being closely watched…

Late last year, I took a look at how another flawed currency system, Argentina’s dollar/peso peg, had splintered during the course of 2001, concluding as follows:

[W]hen the dominoes of finance finally fall, they fall quickly. To return to the IMF’s grim textbook: “The crisis broke with a run [on] private sector deposits, which fell by more than $3.6 billion (6 percent of the deposit base) during November 28-30.” At that point the game was up. The authorities’ response (notably the introduction of the corralito) should alarm depositors throughout the PIIGS as they mull how their governments might stop precious euros escaping to safe havens abroad in the wake of bank runs at home. The corralito limited cash withdrawals from individual bank accounts to the equivalent of $250 a week (the dollar value would soon fall sharply). And the response to it should worry those now running the PIIGS. Argentinians took to the streets and reduced the country’s political order to chaos. Depending on how you define the term, Argentina had five presidents in less than a month, but none could change the inevitable. The country defaulted on its debt, the peg was scrapped, the peso tanked, and the corralito was replaced by the corralón, the centerpiece of an even tougher regime. Depositors were allowed to withdraw a little more money than before, but only in heavily depreciated pesos. Term deposits were frozen, and transfers of money out of the country heavily restricted. Not so long after, dollar deposits were switched into pesos, and the ruin of Argentine savers, many of whom lost their jobs as the economy crashed, was complete.
History does not always repeat itself. Maybe those remaining Greek depositors are confident that, however battered their nation’s finances, its guarantee of bank deposits up to some $135,000 will hold up through the toughest times. Maybe they have faith that Greece will stick with the euro. And maybe they trust that, should the walk from Greek banks turn into a run, the European Central Bank will do what it takes to put things right. But if they do have any doubts, they can, for now, easily move their euros to a part of the eurozone—Germany, say—where there is no currency risk and bank deposits are blessed with a guarantor that is, you know, solvent. Thinking like that is how a run on the banks can begin. Paranoid? Well, if you were a depositor with a Greek bank, what would you do?
And, if you were a depositor in an Italian bank, watching all this and aware that money is ebbing away from Italy too, what would you do?
I know what the Argentine advice would be. Run.
And if the Greeks run, and the Italians run, who will be next?

And that was written before the hard-left Syriza party was surging in Greek polls…