At Melt Bakery, a hole in the wall that sells ice cream sandwiches in New York's upscale Manhattan neighborhood, you can pay for your guilty pleasure in bitcoin.

And while a few swipes of a mobile app are all it takes to fill your electronic wallet, the novelty, for now, comes at a hefty cost.

Melt is one of several small stores in America's biggest city now accepting the bitcoins, hailed by some as the future of currency.

Investors' interest has been piqued by the virtual currency's surging value while industry insiders see it as an alternative instrument for consumers who want to shop online but don't have access to traditional instruments like a credit card.

It has even triggered an expanding ATM network that lets people turn their cash into bitcoins, and their bitcoins back into cash.