They told me that were at dinner in Paris and some American guy overheard them talking about being from Illinois. When he ask where exactly they were from, they told him "around Champaign", but then added "a little town called Philo."

The American said that he actually knew someone from Philo (who went to the U of I). He couldn't tell them a name though, because he and his friends have always just referred to the guy as "Philo".

I have follow up questions, but I'm afraid it will remain a mystery.