The consent for children is a law that was proposed by the UN -- I believe sometime in the past 5 years. Now no country that has signed is allowed to knowingly permit the transport of children without the appropriate papers. And they're pretty strict about it at the airports! My brother married a Dutch woman, they travel back about once a year from Canada where they reside. One year my sister-in-law went a week earlier than him with their baby, so she had the papers. He also left for canada a week earlier. When she left, she had thrown out the papers because she didn't see how anyone could protest when she was obviously heading to her country of residence -- but she got to the airport and they wouldn't even let her check-in without the papers! She ended up having to call my brother and get him to go to a notary and fax off the papers direct to the airline before she was allowed aboard.
I think if you want unusual laws that are unique to Argentina you will have to contact some lawyers, not just expats. Most laws here are common in other countries as well, however for the oddities you'll need an expert. I know many countries have some very strange laws still on the books simply because it would be such a long process to get them out.