Great idea for a topic, as I have often wondered about this, too. In about a decade of casually looking around, I've only ever seen one homebrew in the wild. At a local game-cd-record store a year and a half ago, I came across a copy of Another Adventure with it's box. I figured it must have come in with someone's collection, as it was sitting in a box with several other boxed games and about 50 loose games. Interestingly enough, given the amount of items with it, that was the only homebrew, as though the original owner just bought that one and was done. The only downside was no instructions, even though there was a huge stack of others.