The director of the USC Annenberg Centre for the Digital Future says smartphones are rapidly becoming the number one way of getting online.
Jeffrey Cole says smartphones have come of age and are beginning to replace the personal computer in terms of sales.
He says while the core use of smartphones is to give users internet functions, the devices have become a lot more.
Mr Cole says at Starbucks and some other stores smartphones can be used to pay for merchandise and some people think it will become a device which can be used for interaction with any type of vendor.
Samsung launched its latest smartphone model, the Galaxy S4, in New York last week.
However Mr Cole says while the new Samsung is an evolution in smartphone technology it's not a game-changer.
"I think the next game-changer is what Google is doing with Google Glass where they're trying to move the smartphone into your glasses, what you wear that's accessible with just movement of your eyes and it's with you 24/7, except when you take them off and go to sleep."
Mr Cole says another development will be foldable screens, which may mean smartphones with bigger screens that people can keep in their pockets.