Even with the domination of smartphones and mobile data, it's still nice to have Wi-Fi access in places. Maybe you don't have a smartphone. Maybe you need to get some work done and that 4-inch screen just won't do it for you. Maybe you're at the airport and you need to conserve your phone's battery. All of the above, apparently, are good enough reasons for AT&T to test a new pilot project that offers free Wi-Fi to users if they're willing to sit through some good old-fashioned advertising.