I saw a lot of graffiti in Buenos Aries and Rio. will contribute
Update: Okay, as promised, here: 
This first one is on the wall of a 
church, right across from the hotel I stayed at in BA.
 
I don't remember where these next ones are from
 
 
Don't let their smile fool you..they're up to something.
 
They're a lot more artistic in Brazil.

That's all for now, but I'll post more later if you guys are interested.