The "easiest" way would be a page/thread/whatever where people could apply for such a scholarship. So first of all if I wanted to be at the conference but I could not afford it, I'd had to think about why I really want to be there and how I'd benefit from it. Then I'd had to elaborate why I cannot afford this in my current situation. Of corse if you do this you'd have to run through a lot of applications. You could higher the entrance barrier a little by setting a minimum word count, so that only people apply who would really benefit from this.

A not to unrelated question: Do you also cover the "winners" travel, etc. costs?