Following up from Whizkid's post, it seems most of US and Canada are divided into 8 zones (Zone Z-15 to Z-22).. and flights within the cities in Z-15, Z-16, Z-17, Z-18 are for 5k miles, return.. but anything within the zones for others, or from one zone to the other is a flat 30k miles return..

Depending on how far u wanna fly, this can give some great value on Jet Pesos..

ah.. im getting that feeling of a day well spent..