Will you have a "digital wallet" in your future? Will it become a vital interface between you and practically everyone you deal with while traveling? Lots of folks are betting yes. Broadly, the idea is to exchange old-fashioned paper and plastic for a master digital wireless system that can be used for all the transactions you now perform using the contents of your wallet or purse.

You've already seen elements of the digital wallet in use when you travel. Travelers download their e-tickets to a smart device, and airlines can scan and accept the visual display in lieu of a paper boarding pass. Commuters use digital tickets to pay for subway rides as well.

The question remains: Will you be able to leave your wallet behind and go all digital? Here's a primer on what you can expect from digital transactions when you travel now and in the coming years.