Like opening a Christmas gift only to find it full of socks, we had such high hopes when we first saw this mount that lets you dock your iPhone to your DSLR. But sadly, the Flash Dock is a bit of a disappointment.
Imagine all the things you could do with your iPhone tethered to your digital camera. It could pass along GPS coordinates for automatic geo-tagging. You could enjoy extra-large image previews. Your iPhone could serve as a cheap app-based intervalometer for making time lapse videos. In theory, you could even capture clips from a live feed taken from the camera and immediately post them to YouTube. Heck, your phone could even suck power from your camera's hotshoe, keeping its battery charged.
Sadly, the Flash Dock does none of the above. It can access photos directly from the camera, but you'll need an Eye-Fi card and a constant wireless connection which will suck your battery life. It can also be used for geo-tagging, but you'll need a camera that can pull that data from a Bluetooth connection. Or, manually sync location data to your photos at the end of the day.