Yes... Skype works great. www.skype.com ! They bridge calls to land line phones for about 2 cents a minute and for about $40USD a year, you can get a telephone number that people can just dial to ring your computer. For example, I have a Los Angeles 310 number that my friends and family from back home can use to call me.
The sound quality is better than that of calling cards. They also have call forwarding to any phone. When I'm not by my computer, my calls are forwarded to my prepaid cell, which has free incoming calls. Skype charges the same 2cents a minute.
Actually I downloaded Skpe yesterday evening. Unfortunately none of my friends are on it so I haven't had a conversation with it yet. I did notice that there were a number of Argentines using Skype in the search function. But none of them were listed as Skypeme, though. What I'm also wondering if for instance I subscribe to Vonage (or another service) in the US take the adapter to Argentina with me, if I would be able to use it in BA? I really need to be able to have a local North Carolina number for work. NC is where my clients are.
Dialpad is decent, and the weird thing is you can still set you're "dialing from" country as Canada/the States, so you don't even get charged a higher rate then calling from home. I pay .02 cents a minute for calls in NA, if I set my dialing country to Argentina I pay .03 but like I say, it doesn't seem to care, don't know if maybe it is tracing on my IP though for country of origin and recalculating based on that.
Vonage for the time being doesn't have Argentina as one of the countries that it covers. So it looks like I'll be in BA with NC/SC local numbers. If I call to Argentine numbers the charge varies from .05 to .07 cents and .27 for mobiles. I'll probably pick up a mobile in BA. What I'm curious about is how many areas are covered by broadband internet access. I will absolutely need it for work. Also how reliable it is.