While researching the wu-1a I ran across a new company selling hardware to hook either a cannon or a nikon to any IOS device. I bought one and it works great! I am no professional but I was really impressed with what it allows me to do. It works great on my D7000 and I am prettier sure I saw D300 on it's compatibility list. Just do a search for camranger.
By the way this is my first post, I am really looking forward to browsing around and learning as much as I can from everyone. My wife Recently purchased me a D7000, SB-700 speed flash, 70-300mm zoom and of course the 18-105mm lens, I have the 50mm f1.8 coming but on back order. With the edition of the Camranger wifi set up now I am looking for a good tri-pod that will let me get low as well a decent height.