At the moment, DesbloqueioBr is selling its hack for a pretty penny. According to the Agence France-Presse, "DesbloqueioBr plans to charge between 250 and 375 dollars to unlock an iPhone." Those figures just about match the cost of the subsidized 3G iPhone if you buy it with a contract.
If you're desperate to unlock your shiny new Apple product, be forewarned. The company says the hack isn't perfect, and that some users might run into trouble.
The iPhone Dev Team also looks like it has cracked Apple's code. Personally, if you really, really want to unlock the iPhone, I'd wait for the iPhone Dev Team to give away the unlocking software for free, rather than pay ~$300 for it.
It's bound to happen, sooner or later.