Skype. The whole world can talk for free.
I had a lot of people tell me how great Skype is, but I never got a chance to try it out until today when R32argent installed it on his computer. It's awesome! The voice clarity is really good and we were able to talk no problem. Well, you have to be careful when you talk at the same time, but it really does sound like they are right there with you. It's bizarre when you remember that you're talking to someone on the other side of the continent. The best part of it? It's all FREE!