Ever wanted to chat to someone online using your real voice rather than text (eg. email, SMS, Instant-messaging, or even real snail-mail letters)? I've always had an eye out for any application that will do this without requiring an expensive subscription. It's technically known as Voice-over-IP, or VoIP.
Well, I've found one. Well, my mate Jon did. It's called Skype and once you've downloaded it, installed it and signed up, you can chat for free to anyone else using skype using just a microphone and speaker plugged into your PC. I'm not sure about bandwidth requirements, as I'm on ADSL 512kbps so slower connections may not be so great. You still ought to be able to handle a reasonably decent quality conversation. It's secure and encrypted so noone can listen to you uninvited, they appear to support conferences although only the Windows version of the software can host them at present, and it's better than mobile or (just about) normal landline clarity. We did notice a tendency to go metallic or jerky a bit when you suddenly start doing other things online although 512kbps should be plenty for any type of half-decently compressed audio at all, but it's pretty cool otherwise. You can also chat/instant-message people if you're not in the mood or not set up for audio.
They also mention "SkypeOut", a way of calling plain non-internet phones all over the world (yep, this is where they try and make their money) with a pre-pay charging scheme. It seems real cheap though - 1.1p-ish per minute for most countries they support.