James
If in the Philadelphia area, try Capogiro Gelato. It's quite good. About 10 years ago, I used to find their pint sized gelato (including Fico Nero/Black Mission which was outstanding) at Whole Foods in New Jersey. They really pushed locally sourced ingredients, except for tropical fruits. I suppose local is a relative term.
The only bad press I saw about them was about their fig, goat cheese and balsamic gelato which was in an otherwise glowing review.
Thanks for the tip, I will actually be in philly at the beginning of October for a wedding and I will definitely check it out!