In late 2011 while on the Argentine side of the Falls, my husband and I went over to "Foz" by local bus from Puerto Iguazu in Arg (a few pesos only each way) expecting to return to Argentina by the same bus route after an early dinner in Foz. But the last bus back was at 5pm. The restaurant called us a taxi - expensive. Another local bus from the same Arg town's bus station goes back and forth to the Brazilian Falls' entrance frequently but its last bus back was also at 5pm. Brazilian cabs back to Arg cost double BA rates after bargaining. The town of Foz was dead boring. That town wasn't worth our research. Ditto the recommended restaurant we used in Foz (poor food, tiny portions, 3 times the cost of a BA meal out and a complete lack of atmosphere). However, Brazil's side of the Falls and particularly the Bird Park (a 5 minute walk from the Brazilian falls' entrance) were very worth visiting. If you go to Brazil in the morning, you won't have the expense and hassle of taxis. Also, I don't know if Brazil is still charging North Americans and Australians its hefty reciprocal entry fee.