Making phone calls to Buenos Aires, Argentina - AND 3G!
Calling a friend generally consists of picking up your phone and dialing the phone number your friend has given you. Giving your phone number to a friend generally consists of telling them the same number that was assigned to you by your phone company. This doesn't necessarily apply in Argentina.
This is a picture of a back of a sheet of paper our spanish teacher used to explain the phone system here.
1. The base phone number in Argentina is 8 digits, i.e. 1234 5678
2. The area code for Buenos Aires is 11, so 11 1234 5678
3. Unless you're using a cellphone in which case it's 15, so 15 1234 5678
4. To call a cellphone from a landline (which, btw your landline will need to have a special plan to do) you use 15.
5. To call or SMS a cellphone from another cellphone you use 11, not 15.
6. To call a landline from a cellphone you also use 11.
7. When receiving calls from a cellphone the caller ID will appear as a 11 number.
8. When receiving SMS's from a cellphone the caller ID will appear as the full international +54 number.
And for international (incoming) calls...
1. The country code for Argentina is +54
2. You never use the 15 area code when dialing into Buenos Aires, cellphone or landline, you always use 11
3. You might think.. "ok this is easy enough, so the phone number would be +54 11 1234 5678" and you'd be right... UNLESS you're trying to call a cellphone.
4. When calling a cellphone, the telecom company here has decided to also insert a '9' directly before the area code into international incoming calls. So the number would actually be +54 9 11 1234 5678
So to sum up. My phone number here is 15 3346 9192. If you want to call or sms from a cellphone here it will actually be 11 3346 9192. If you want to call me internationally you'll dial +54 9 11 3346 9192. And hopefully you don't need to call me from a landline in Buenos Aires, cause it probably won't work.
Here's a useful reference I found on the topic: Calling Argentina
== 3G with Claro in Argentina ==
My phone company here is called Claro. A couple quick searches on The Google for an APN username and password and password for Claro were helpful :) . There's no username/password as usual, and the address is internet.ctimovil.com.ar - set that up on your phone and presto! 3G. Much easier than actually figuring out how to call someone. Claro data rates aren't cheap though. I think I'm probably paying close to 10ARS/MB, or roughly $4CAD.
For future reference this looks like a useful list of the APNs for most carriers world wide.