Free calls US and International

NetZero Voice-over-Internet Protocol (VoIP) Service for Dial-Up and Broadband lets you call Anyone, Anywhere in the world, Anytime for Free.

Setup an account with Netzero and you can make calls in the US and Canada for free. They also give you a local US number. So international users can call you for free. i.e. PC to Phone!

Thanks to my friend Sabir for this link.