Cell phone bonus is one answer!!!
There are some promotional callings from cell phone that if you have a pre paid cell phone, you can make calls cheaper to yor family or friends. Also if you call for the same company as your account this calling is cheaper yet.
In my opinion, in Brazil, Vivo and Oi are the companies that have the best promotions for bonus, is good to have both chips accounts.
For the people who will stay at brasilian coast is better for the communication, if you have the lap top, you can have one those wireless internet.