what should the format be...

<p>for those of us that were deferred and want to send additions to our resume</p>

<p>should it be like a mini resume or like a letter? do you think they would just be too lazy to read the letter and would opt for something more organized and concise?</p>

<p>I suggest sending a concisely written letter highlighting the new information.
""Since I sent in my application, I have been awarded xyz. I'd appreciate if this information could be added to my file."
If there are several awards, you can make a list for greater clarity, with info about what they are ("awarded to only one person in my state," "juried competition" and so forth).
You could send in a new resume, just make sure that you note the new one replaces the old.</p>