Whats something fun to do on Civilization IV BTS?

Gonna play Civ in a lil while. Whats something fun to do besides beat the game in a normal fashion? For instance I poisoned all enemy crops using Fallout Tile in World Builder... Any ideas?Whats something fun to do on Civilization IV BTS?
Whenever someone declares war on you make their entire civ fallout and desert (That is my favorite :] ). You could also try making everyone hate ONE civilization and lead a crusade against them (This is also very fun). If you are playing on the map type with the old world and new world try taking over the new world before anyone else can but heads up barbarians are everywhere.Whats something fun to do on Civilization IV BTS?
I played a game once where I progressed as normal into the modern era and then unleashed massive armies of barbarian marines and tanks on the world with World Builder, seeing which nations would survive and which would fall.