I received my Phantom 3.  I can't fly yet because I'm waiting for my iPad to be delivered.  I have been playing around with the camera and taken some pics and video.  I was hoping someone could explain what the different files are on the SD card.  I am familiar with the Quick Time Movie and JPG files but what are the SRT and DNG files?

I can't speak for SRT files, but DNG files are photos that you shot in RAW format.

SRT are files containing subtitles. These subtitles contain somme flight information : GPS position, heigth, ...
Viewing your videos with tools Luke VLC allows you to view these subtitles.
DNG is the Proprietary RAW format fromage Adobe (like CR2 or CRW for Canon ans so on) : this is not a "universal " format like most people think as a universal format doesn't exist.

Thank you for the replies.

By the way, the SRT subtitles are turned ON and OFF in your camera settings:


This video shows captioning Turned On: