“Understanding and Obtaining the Brazilian CPF – A Primer for Foreigners

Unlike the United States Social Security cards, in Brazil tourists and other non-resident foreigners and even foreigners who are domiciled overseas are eligible for a CPF, which stands for Cadastro de Pessoa Física (Physical Person Registration). However, as explained below the process is to cumbersome to be useful to anyone who will be in Brazil for less than a couple of months and is not planning to return.

In Brazil, the Cadastro de Pessoa Física (CPF) is like the Social Security card in the United States in many ways. Each person who wants to participate in the official economy will need a unique CPF number which identifies him and his files in a variety of contexts including banking, credit applications wherever they are made, purchasing and activating a cellular phone, renting an apartment, and just about any other transaction which a person would engage in if he intended to stay in a country for more than a month.”

A lot more info here.