I felt sus­pi­cious at first too, but after try­ing Voip Stunt I was stunned! They are actu­ally free although as you prob­a­bly expected, there is a teeny wee­nie catch.

The catch:
Free calls last for 1 minute unless you have credit in your Voip­Stunt account. You have to pur­chase a min­i­mum of 10 Euros (~$14) every 120 days to keep your account active.

In a nut­shell:
For $3.5/month you can make free PC-to-Phone calls to the fol­low­ing coun­tries:
Andorra, Argentina, Aus­tralia, Aus­tria, Bel­gium, Bul­garia, Canada, Chile, China, Colom­bia, Cyprus, Den­mark, Fin­land, France, Geor­gia, Ger­many, Gibral­tar, Hong Kong, Hun­gary, Ice­land, Ire­land, Italy, Japan, Latvia, Liecht­en­stein, Lux­em­bourg, Malaysia, Monaco, Mon­go­lia, Nether­lands, New Zealand, Nor­way, Panama, Peru, Por­tu­gal, Sin­ga­pore, Slove­nia, South Korea, Spain, Swe­den, Tai­wan, Thai­land, Turkey, United King­dom, United States, Venezuela

I per­son­ally think that this is one hot phone deal, espe­cially if you make a lot of inter­na­tional calls. Give Voip­Stunt a try, with­out buy­ing any credit (and with­out using your credit card at all), and decide whether it suits your needs.