(Steve Marcus/Reuters)

You can pay for groceries by scanning your phone. You can board a plane after scanning your phone. You can check your bank account balance and order dinner and show proof of insurance and buy pants and watch a movie and do essentially anything with your phone, because your phone is always there. Your phone is always in your hand, and even when it isn’t in your hand it is in your bag or your pocket, ready and waiting, secure in the knowledge that you won’t be able to wait long before compulsively checking it again and again.

So if the phone has replaced the credit card for many, and if the phone has replaced and consolidated so many other things, it stands to reason someone would ask: We’re always carrying around driver’s licenses, so is there a way our smartphone could replace that, too?

This idea is being considered in a few places across the country, states that could function as test subjects to see if such an idea can catch on with the broader populace. The Delaware legislature passed a bill last week asking the state’s Division of Motor Vehicles to “study and consider issuing” digital driver’s licenses that could replace the traditional plastic ones.

This bill notes that since people in the state are already using their phones for things such as working and banking, so giving them the option for a digital driver’s license could be a way of “increasing convenience” for drivers in the state. And it would just be an option, giving drivers the choice of loading it on their phone or sticking with the plastic card wedged into a wallet.

The First State isn’t the first to suggest such an idea — Iowa said last month it planned to have a pilot program testing smartphone driver’s licenses — but Delaware wants to beat them out of the gate, if possible.

“We’d like to go first,” said Jennifer Cohan, head of the state’s motor vehicle division, told DelawareOnline. “If it works for Delaware, then it will be a new option for Delaware citizens to show proof of driver’s license and identification.”

The bill passed last week notes that Iowa is exploring this concept, but reasons that with the state’s smaller population (Iowa has three times as many residents), Delaware “may be in a better position to adopt new digital driver’s license technology.” Arizona also hopes to get into the race. A state senator there proposed a bill that could similarly lead to electronic driver’s licenses.

In many ways, these proposals seem inevitable, a natural extension of the process that began with phones replacing address books and cameras, continued as they became travel agents and taxi dispatchers and now evolve into a handheld, rechargeable excuse not to carry around cash or a credit card. This is, of course, not a universal truth, and the smartphone-as-essential-gadget trend is undercut by the realities of actual adoption and usage; as of last year, about six in 10 American adults had a smartphone, compared to the 90 percent who had some sort of cellphone, according to the Pew Research Center.

Unsurprisingly, these devices are more common among people who are wealthier, younger and have more formal education. Yet the popularity among 18- to 29-year-olds — more than four in five of whom have smartphones — seems important, not just because this may be the only kind of phone some of them know, but because this is an audience that is being taught how easy it is to replace cash with a thumbprint.

Still, there are possible headaches that could accompany the idea of replacing something as personal, and as frequently needed, as a driver’s license. A patchwork system could emerge, with some states accepting the digital license and others requiring a plastic one, which could be a headache for a driver who travels to an area where police require an actual license if they pull you over. Phones get lost, dropped between couch cushions or left atop a bar counter. Phones also require juice, so a driver pulled over with a dead phone may also be a driver pulled over without any proof of a license.

And, of course, smartphones are not just phones. They are repositories of our personal and private information, messages sent between loved ones and banking information, all kinds of things you would not necessarily want to show a police officer or bouncer at a bar or whomever else may require proof of identification.

Personal information offers an entirely different set of possible concerns that could emerge if the digital licenses enter the physical world (so to speak). The issue of privacy and our phones has been considered before by the U.S. Supreme Court, with the ruling ultimately speaking to concerns about government prying that reach back to the country’s earliest days.

Justices ruled unanimously last year that police have to get a warrant before they can search the phone of someone who has been arrested, drawing an explicit link between the Fourth Amendment’s ban on unreasonable searches and warrant-less searches of phones.

“Modern cell phones are not just another technological convenience,” Chief Justice John G. Roberts Jr. wrote in the court’s opinion.

Roberts noted that these phones, with their ever-increasing capacity, offer a possible intrusion of personal information that was previously impossible to carry out with a single search.

“The term ‘cell phone’ is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone,” he wrote. “They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers.”

Drivers may have the option to add “license” to that list at some point in the relatively near future. It remains to be seen how they will feel about handing their computer-camera-video-player-diary hybrid to a police officer who has just pulled them over.