i just arrived last week. Came with macbook pro and a netbook. I declare the netbook, because it is a gift. The macbook it is mine to come and go. The girl in front of me have a backpack, the official asked her to put the bag on the belt, and she said, but I have a laptop, it is safe. and then the guy asked her, did you purchase it abroad, and she said yes, and also had another laptop in another bag. They stop the belt and took her for questioning. I think she made the mistake of trying not to put the backpack in the xray and she gave no choice to the official to questioned further. I usually if questioning tell I have a laptop and that is my working tool and I don't reside in Argentina and my equipment goes back with me on departure. I been asked for green card or visa stamps proving I live or have residence abroad. I would recommend to be polite and even if you are bringing equipment to sell in Argentina, make the point is yours. For large items as tvs or expensive stuff, definitely fill the custom forms and pay the tax, as other members noted, you will still save money compared with the same item in Argentina, and you will avoid being charge of smuggler offenses, and that could be a mayor headache.