And I don't just mean the surplus food as has been mentioned in other threads. I mean that in an XP or in a super patch civ3 should have more tradable goods like:
tabaco (although using this to make people happy could put down your pop. growth)
Coffee beans
jewls sorted in type: diamonds, rubies, opal, topaz etc
peat
beer...
Hey, even marijuana! Or cocain, and trading this could get you in trouble with other civs. They could even pose economic sanctions on you through the UN! No, wait.. I'm thinking of another game... namely SMAC!
Anyway, could the editor create new resources to trade, even strategic resources like nikel or sand for making silicon chips? SAND? wait, I'll get back to you on this...