The simple credit card is about to get a makeover.

Next month, Citibank will begin testing a card that has two buttons and tiny lights that allow users to choose at the register whether they want to pay with rewards points or credit, at most any merchant they please.

Other card issuers are testing more newfangled cards, including some that can double as credit and debit cards, and cards with fraud protections baked right into the plastic. One, for instance, shows a portion of the account number only after the cardholder enters a PIN.

The microscopic engine powering the plastic will help breathe new life into a 1950s-era technology  the black magnetic stripe found on the back of the 1.8 billion credit and debit cards circulating in the United States. Much of the world has already moved to using more advanced cards, like the ones in Europe that require a PIN and use a chip instead of a magnetic strip.

Even with the innovations, no one knows how long plastic cards will reign. They may eventually be rendered obsolete by technologies that will transform consumers’ cellphones into virtual wallets, and a large number of companies, including Visa, MasterCard and Apple, are developing these. But several card analysts say it will probably take a while before any one technology standard becomes available across all phones and merchants.