If you're interested in my art that I first posted, I have a DeviantArt account here: http://polyfrag.deviantart.com
So the next idea I have is, what if the smartphone had 3 or so "mini-RADARs"? Ie, they would rotate inside the phone, and you could use it to orient yourself with other devices or cell towers. It would give a centimeter-accurate GPS and orientation meter. Instead of calculating the time-delay between cell towers or signal strength, and triangulating position based off of that, or off of GPS satellites, which is only accurate to a meter usually (or was it 10 meters? it was something that was not useful for determining a person's position with respect to other people), the mini-RADARs would calculate the relative angles of the cell towers or any other devices, and use the angles to calculate relative position and orientation. This may also make it possible to point the phone at something and get information that way, like another person holding a smartphone, or a store window, or an apartment window on the 5th floor (maybe they have a home blog?) This is similar to the infrared LED like in remote controls also found in the LG G3 (they have all the codes for all the remote controls you can use), but would be longer range and more powerful.
[Edit] I should also explain how directional Bluetooth or miniRADAR works. In normal RADAR a radio wave is bounced off of a metal object. But for miniRADAR there would be a little dish that can only receive signals and send from a certain angle and direction. If it rotates very fast and tried checking when the signal works or doesn't maybe by trying to keep the target in and out of it's rim of reception, it can detect an angle.
 The cell tower could work by the same principal, with a mini-RADAR, to tell the client their angle with respect to the tower. The tower or the client could send a packet or datagram with one number one way, and a different one the other way, and depending on which one is received back, it determines the direction. A whole bunch of numbers could be sent in a series, and the combination of them is used to determine the angle. One mini-RADAR of the three could be facing the other side that the other one isn't, in the anti-parallel direction, and the third could assist. I assumed three were needed, if perhaps they were locating at opposite ends of the device, if perhaps the electronics inside interfered with the signal. The cell towers could implement these mini-RADARs first perhaps, while the older smartphones were "phased out".