Per my previous post, Dan and I visited the Brazilian and Argentinian sides of Iguazu Falls – in the same day – last November. Long day, but totally doable with a bit of planning. We organized our day by having our hotel arrange a cab (or really their friend who had a minivan and was willing to drive…) to pick us up in Puerto Iguzaú at 8:00 a.m., take us to the Brazilian falls (including through the border crossing), pick us back up at 1:00 p.m. and then drive us to the Argentinian Falls (border crossing again included), where we would explore until 5 p.m., when we would be driven back to our hotel. We arranged this for $75 US (tip not included), including waiting at the border crossing (which only took 5 minutes and we did not get out of the car). If you are short on time and have money to spare, I recommend this option. We booked it on arrival through the front desk. We had JUST enough time to fit this in and you may be rushed if you do not have the necessary VISAs pre-arrival.