“Depending on whom you ask, bitcoins are a goofy geek invention with as much long-term value as Monopoly money — or a technology development that could transform currency the way e-mail and texting have transformed correspondence. A type of digital cash, bitcoins were invented in 2009 and can be sent directly to anyone, anywhere in the world. You don’t have to go through a financial institution, which means no fees and no one tracking your spending habits. With a current market capitalization of $1 billion, bitcoins are beginning to be more widely accepted. You can use them to pay for a pizza or [finance] your child’s college education.”