I only know about him because of Renaissance Technologies, which is renowned in some circles as being extraordinarily hard to get a job at. They're known for snagging repeat Putnam Fellows. Last I heard Reid Barton ended up there.
Near the bottom you see this guy talking about his startup ideas and Drew Houston replies and asked him if he wants to help with Dropbox.
(See this recent post on tarsnap: https://news.ycombinator.com/item?id=7523953 )
Well, I was happy. I didn't finish my hw that week. :)