Phone the USA and Canada for Free

This is a little confusing, but from what I understand, if you want to call any number in the USA or Canada, it will cost you nothing if you use Skype. I am sure that there is no such thing as a free lunch, but maybe I wll be proved wrong.
This from News.com.com

Skype users can now make free SkypeOut calls to traditional landline and mobile phones in the U.S. and Canada until the end of the year, the company announced Monday.

Skype, which offers software that allows people to talk over an Internet connection using their PCs, is trying to get more people in North America to use its SkypeOut service, which typically charges people to make calls to a traditional or mobile phone. Skype calls made between PCs are free.

While Skype executives are hoping to drum up more business with this promotion, SkypeOut calling is free only until the end of 2006. What's more, calls made to and within all countries other than the U.S. and Canada will continue to incur charges at current rates.

GO FOR IT! The whole issue of "in" and "from" and "to" is what is confusing me, but if you don't have to give a CC number and you can call, sounds good to me.