Bitcoin breaking into mainstream with companies and consumers

Earlier this year, Mary Fons joined the bitcoin economy. She uses the digital currency to buy gift cards and office supplies. Her partner reimburses Fons with bitcoins for his portion of the rent.

Unlike many of the currency's early adopters, Fons isn't a nerd or a libertarian. She is 35, lives in New York and co-hosts the Love of Quilting show on public television.

"Why bitcoin?" she said. "Because I want to have options. I think it's a beautiful thing open to everyone."

Fons has company. People worldwide have opened 41 million bitcoin accounts, according to the Bank of England. While the total value of bitcoin commerce is not known, Gil Luria, an analyst at Wedbush Securities, estimates global spending on goods and services has doubled in the past year.

Parents are dispensing allowances in bitcoins so their kids learn to be digital citizens. Marijuana smokers are buying buds from bitcoin-enabled vending machines.

Consumers in emerging markets such as Brazil and Russia are starting to use bitcoin to hedge against currency volatility.

By far the most popular virtual currency, bitcoin was created in 2008 by the mysterious Satoshi Nakamoto, a programmer or a group of programmers. Most currencies are managed by central banks. Bitcoin has no central administrator: a network of volunteer computers validate transactions, which require encrypted electronic signatures.