Ok, quick follow up. If you want to get a cell phone WITH contract, you MUST have a DNI. Otherwise you will have to find someone with a DNI who is willing to get the contract under their name, and just have the monthly bill sent to your home.
I'm not very familiar with San Telmo but I do know some things about the SIM card. First you have to make sure that you phone is unlocked. Once that is done then you can go to any provider like Claro (boo), MoviStar, or Personal (my favorite). You can find stores everywhere you go. You can buy a SIM w/o contract and use a tarjeta to load minutes onto it. I believe if you want a contract plan you would have to buy a new phone as well.
Welcome to the neighborhood, we live on Brasil right in front of the park. Not too impressed with the local Coto on Brasil, we generally make a Carefour run, the one in Avellaneda being the closest that I'm aware of. PM me if you want to catch up for a cup of coffee when you arrive
I personally hate Moviestar. When I lived in Spain they would always wake me up on a Sunday morning to ask me if I wanted to sign up for one of their latest promotions.
the san telmo mercado is great for vegatables, meat and second hand cloths...there are all the services and items you need right around where you are going to be living, (and for much less than in palermo) you just have to start asking....You want an umbrella fixed? someone can direct you to an umbrella repair store! (and unfortunately, i never wrote down the address!) 130 collectivo will get you to so many places... and you will have some of the best old time restaurants and bars for much better prices right around park lezama... i think you did a good move