Can I stay overnight in Foz do Iguazu w/o Brazilian visa?

Angieinba: Thanks for the heads-up about the Embassy's early closing hours!

EliA: Please (anyone) correct me if I'm wrong, but I've read online that the fee for getting *caught* without the visa is USD 150. Pretty steep, isn't it?!

Gaby: Great idea about buying the entrance fee to the Brasilian side of the falls in advance to show with my tourist visa application! It's too bad they wouldn't let your family through!

Thanks for all your helpful comments and suggestions!
Miro, I don't know about the fee for getting caught; no one has mentioned it to me. I recently talked with a friend who made the cross and she said there is no Brasilian checkpoint; she left Argentina, got an exit stamp, spent the day in Brasil, and then got an entry stamp to Argentina on her way back. I'm sure there are multiple places to cross so maybe this isn't true for all spots, but it seems like you could just ask someone where to cross and I'm sure it's common knowledge up there. You're right, though, if the fee is the full visa fee then it might be a risk not worth taking!
Miro, you are welcome!
I dont know if you are living in BA or just staying here for some time. But if you plan to live here, I would definetively apply for a tourist visa in order to go to Brasil. I mean, if you get caught you said you have to pay u$d 150; and if you have a visa for around the same amount of money (not sure exactly how much) you can visit Brasil anytime.
Brasil is a beautiful country, with great beaches..Maybe in the future..why not a trip to Salvador, Porto Seguro, Morro do Sao Paulo..??