For anyone else interested: Nemo was able to answer this question because StackExchange has a Quarry http://quarry.wmflabs.org/-like public query interface of their own. You should go play with it right now: http://data.stackexchange.com/
It's worth pointing out one major difference between their Quarry-like thing and our Quarry. I love both, btw. But our Quarry suffers because the only public database we have is raw and has a schema meant for OLTP. StackExchange's is clearly hitting a well organized OLAP style schema. Something to aspire to, perhaps collaborate with them on.