Bitcoin exchanges are reporting a surge in interest from Greek users faced with shuttered banks and capital controls.

The #bitcoin market just needs a little GREASE to get unstuck. #Grexit price targets $610 and $1250 pic.twitter.com/A0ZJ0ppdfZ — Tony Gallippi (@TonyGallippi) June 28, 2015

Ahead of a referendum on creditor proposals for Greek reforms in return for vital bailout funds, this week the country's banks are shut and a EUR60 daily withdrawal limit has been imposed.The move appears to have prompted many to turn to cryptocurrencies. Bitstamp says that trades from Greece are currently up 79% on their 10 week average, while German and Chinese-based exchanges are also reporting a surge in users from the troubled country.Whether Bitcoin is of much immediate use to cash-starved Greeks is debatable: according to CNN Athens is home to just half a dozen merchants - including a yacht rental outfit - that accept it.Meanwhile, the crisis appears to be having an effect on Bitcoin's price, with the currency's value rising from around $245 a week ago to $265. Some are betting on a far bigger surge if Greece leaves the Euro, with Bitpay co-founder Tony Gallippi predicting that the $1000 barrier could be broken.While some cryptocurrency speculators may be praying for Grexit, one man is attempting to prevent it with an ambitious crowdfunding campaign. London-based Thom Feeney has set up a page on Indiegogo in a bid to raise the EUR1.6 billion needed by Greece to pay off an IMF bill.Although way short of its daunting target, the campaign has raised an impressive EUR200,000 from more than 12,000 funders, perhaps tempted by perks such as postcards from Greek PM Alex Tsipras and bottles of Ouzo.Feeney insists that the effort is not a joke and that all the perks will be delivered.