As far as the rest of your website, for me personally, I trust websites that are polished, simple, and have professional copy. I was really impressed with Swipe.com recently and immediately trusted them.
I think it's a nice concept. People will perhaps be more inclined to give if there was some sort of feedback mechanism. Something that will tell a complete stranger that the guy who was an ipod shuffle for his birthday deserves my $5. Perhaps if I knew that this guy gave $10 to someone else last week for a school textbook? Just thinking out loud.
Will you do me a favor and check out my startup here too: http://news.ycombinator.com/item?id=3073337
Thanks