You can check out www.deltathree.com for free calls to USA _and_
Canada.  It also works for other countries, but with charges.
(At least it's still cheaper than direct calls by phone.)

I recommend as equipment a headset which has both a microphone
and earphones, else the other party on the normal phone will hear
an echo of himself.  I've already been talking to one of my friends
near Vienna, Austria, this way.

greetings by(e) InK - Ingmar Krause
ERlanger drehORGEL-Trio, Familie Krause, erorgelt@erlangen.franken.de