Most of us outside the US know that when a company in the US tells you to call their toll-free number (1-8xx) it 's not gonna work... you need to be located inside the US to take advantage of a toll-free call. Until Skype came along. I experienced that today... I had to call an 1-866 nr of one of my suppliers in Dallas, TX. I also maintain a small credit with Skype for calling landlines or mobile phones worldwide. Each time I call someone in another country, the call is transferred via IP to a local 'outlet' that then reaches my correspondent via the normal telephone operator and Skype charges me a 'local' call.
Same fashion, if you Skype a US toll-free number, the destination does not reject your call as 'coming' from outside the US since Skype carries it to a US look-alike caller somewhere in the States. Long story short... not a penny leaves your Skype credit for a toll-free call like this, but most important, the call indeed takes place flawlessly and your correspondent doesn't even have a clue whether you're calling from Hoboken, Belgium or Hoboken, NJ.
Skype's the best invention since sliced bread, innit?