While at SXSW, I got to try the Sony Cybershot DSC QX10 camera. This is the camera that wirelessly connects to the smartphone and takes over the camera. The 18 megapixel camera can bring higher quality photos into your camera.
The add-on lens is one of 2 in the Sony line (QX100 being the higher-end version). The advantages of this camera are you can use your smartphone to capture, then upload photos using the 3G/4G service. You can also disconnect the lens to hold up high while you watch the viewfinder to take the pictures. Finally, the optical zoom of 10x lets you get close-up shots of about 20 feet away.
The disadvantages are this lens needs to be charged to use, although you can switch out battery packs for continued photos. The other downfall is how the lens weighs down the smartphone. If you have ever taken a one-handed photo, the only way to do it with this system is to detach the lens. That could cause for blurrier pictures.
One feature request would be some type of adapter that could have the lens sit above or below the phone. That way, I can use the screen in a selfie-environment.