I don't know about the Plus system, but many ATMs have the 'Link' logo. I was told by my bank in the states that the link system would make withdrawing easy. I have foud that I can withdraw from just about any ATM for a fee(with or without the link logo). Most charge near $5! Banco Provencia charges less, at least for me.
Wiring money is a different story. I wanted to have a small sum wired monthly from an account in the states to an Argentine account. Went to Citi and a few others. All told me that it was a long drawn out process that included much paperwork. I don't know how accurate that is because I've heard, many times, that one bank employee will tell you something totally different from another employee of the same bank. Easiest thing for me is to just keep withdrawing from ATMs and paying the fee. I know it is stupid to let the banks nickle and dime me to death, but hey, I've fallen into a pit of laziness.
ATMs are everywhere. Wiring money is not so easy. Many banks require you to have an account with them for some time (6 month?) before you will be able to transfer money from abroad. Plus to get an account you generally need to be a resident (there are some exceptions). Exchange agencies have less requirements and lower transfer fees, but not all of them operate transparently.
And fees are not so miniscule either.
My atm card has the cirrus, the exchange, and star logos on the back, not sure which I use specifically, but I do know that I have never paid a fee here to use an ATM, but my bank charges me like $.50, and some international exchange tax, but they give me a great rate on the exchange, and on previous trips, I have withdrawn dollars, but so far, have yet to be able to find an ATM that has them, although they all ask if I want dollars or pesos.
I have used western union before as well... but I think there is a cap to how much you can send.
My bank accounts in Canada use the Plus system and it's one of the most common ones on ATM's here. Although my withdrawls are free on my Card if I use it in Canada, they charge me an international fee per transaction which is about $5. Certainly worth withdrawing money from different banks because many will only let you take out 500 pesos each time and other will let you have 1000. The best deal I've found was to withdrawl in US dollars because some machines will let me take out $500, which is even above my daily limit technically. The hassle of exchanging the money isn't really worth it though.
From what I've heard, you can't open a bank account here unless you are a resident and have the famous DNI book. Some people get around this by having an Argentine friend open the account but that's risky business. Transferring money into the country is supposed to be hard to do as well although I've heard it's not so hard to transfer it out.
If you aren't in Argentina yet, the whole banking thing is something to do work to learn about so that maybe you won't pay so much in bank charges. Another thing is that if you have an account with an international bank in your home country, that doesn't mean they'll let you open an account here.
I'v made inquires to apatment agents for short term apartments and they want a deposit sent to them through Westen Union. I have read on Craigslist that this is a NO NO, this is an invatation for a scam. Does any on have a comment or a suggestion?
I guess you also need to go to a specific branch of a specific bank to a specific person. And she has to be in a good mood. Then may be they will open you an account. If you are doing it randomly, probability of success is about zero.
Nikad is correct. Depending on which bank you go to (I know that at Banco Provincia you can) you are able to open an account with the documents he specified. However, you won't be able to get a debit or atm card without a DNI. Also, you can have money wired into the country. I've done it, and I did it the day after I opened an account, thought it was a huge pain in the ass dodging around bank executives who thought I was laundering money. The fees for transferring are hefty, between 1% and 2%, though I don't remember anymore. For more information you can email me. Also, if you have an American Express card you can write personal checks from your U.S. bank account to the office downtown free of charge (and they exchange them into pesos at the same rate as an atm) with a limit around U$S2,000/month.