There is a way to make totally free calls to regular landlines in the US.

Here is how you do it. You dial 1800FREE411. This connects you to the US directory enquiry service. You then get them to look up your contact and they then through connect you. I haven't done this myself yet, but it is on the Skype website, so I figure they have worked through the model.

If that is not disruptive to old economy telcos, I don't know what is!