I've got a CUIL but not a DNI, still waiting for that to come through. My company were pretty sure that there are some banks here that will let you open an account with just a passport. Not sure, will give it a go. If I have any luck I'll post up here.If you get a bank account here you can get a local argentine credit card, and depending on which one you choose you can get pretty considerable discounts in shops and supermarkets all over the city, plus you can break and spread payments interest free over several months. Which is nice.