Have you seen Skype?
www.skype.com

I know internet phones have been round for years, but unlike the one I tested a few years ago, this works well.

Never seen this one before. The biggest drawback with many of these services is that the distant user needs to have the same service, so it's fine for setting up a specific point-to-point link, but rather restricting otherwise.

The services providing a direct Internet link to a real phone line seem to be getting quite popular. I've heard some good reports about the Vonage system.