In Reply to: just ring jetstar posted by freeofkids on Saturday, 10. April 2010 at 18:16 Bali Time:
Depends what fare you have booked - if it is the cheapest without a baggage entitlement, you can change it - BUT it costs $90 + $20 for the 20kg baggage allowance.
I did exactly the same thing and forgot about surfboards - called jetstar and they are happy to change - at the above mentioned costs.
Not sure what the story is if you have purchased the fare that includes 20kg baggage.
Good luck - I'd love to know how you get on.