I want you all to download Mumble from http://www.mumble.com/. Mumble is a voicecall program, like Skype. The difference is that on mumble you don't add anyone to call them, you have a server that you join. I have a mumble server, so we'll be using that. Mumble is like TeamSpeak, if anyone knows what that is.
Download Mumble 1.2.4 without skin from the website I linked, then install it at your computer. When done, ask me and I'll help you set it up and connect to the server!