You might not need a mobile carrier by 2020

Wi-Fi is ubiquitous.

No longer the realm of coffee shops and homes, Wi-Fi spans entire neighborhoods. Trains, planes and automobiles are Wi-Fi equipped. Cruise ships have Wi-Fi. Comcast has even made every customer's router into a public Wi-Fi hotspot. That's good news if you're a cell phone user. The more you email, watch Netflix, stream Pandora and surf Facebook over Wi-Fi, the fewer gigabytes you have to buy from your cell phone company. Plus, calls and texts are now able to be sent over Wi-Fi, too. Broadband customers that actively use Wi-Fi on a regular basis save more than $30 per month on their wireless bill, according to a Macquarie Group survey.

So what do you need your cell phone company for?