Crossing the border from Brazil to Argentina is quite easy. However, the bus leaves all foreigners in Brazil's border and goes away, no explanations to anyone. For me there was no problem, just needed to ask, but for the other 2 guys that were with me in the bus (from South Africa and Spain), not so much... After the "exit stamp", we needed to wait for another bus to cross the "Ponte da Amizade", half brasilian half argentinian. This time the bus waited for everybody to stamp the passports and left us in the center of Puerto Iguazu.
Puerto Iguazu, the closest city to the Iguazu Falls from the Argentinian side, is the sweetest little town. This is the view from the Hostel Stop (really good and very cheap, about 5,50 euros/night). Its a very small town, but very colorfull and the people are really nice, the total opposite from Foz do Iguaçu, on the brasilian side.
The Falls are increadible, there's no way to describe them... the most beautiful place I have ever been to. All the suroundings, the colors, the air, butterflies and rainbows everywhere. Its paradise on earth. Kind of looks like a Disney movie scenario, a bit unreal, to perfect to be true, like between Pocahontas and Tarzan.
The "Great Adventure" is a bit expensive, but totally worth it. After a walk in the jungle, with a guide, we go in a boat trip that goes really under the falls.
One day was not enough, so I went a second day, this time with a girl from Israel that was sharing the Hostel's dorm with me. For her, this 2 and a half months trip is a small one, since she's travelling for 6 months, and the normal for Israeli people is 1 year long trips... I wish! We also had dinner together, and got to meet a spanish guy thats traveling for 2 years already, getting some short term jobs in hostels and restaurants now and then.
But the ultimate proof this is a small world was the italian guy from Perugia that I met in the Hostel as well. He's now going to the south of Argentina, maybe we'll meet again halfway.