iCall – A Free Skype Alternative
iCall is a PC-based VoIP application. Like Skype it is currently Free for US calls. Unlike Skype, inbound calls are also Free. You can call any US-phone for Free with the software. If you want someone to call you via iCall, you receive an extension when you sign-up and whoever wants to get in touch with you calls one of the inbound access numbers (there are some in almost every US area code), and then they enter your iCall extension.
Calls to Canada are also free with iCall. There are access numbers in a few Canadian cities.