Talkster's Free World Dialing gives you free long distance and international calling from any phone, on any network. There's no registration, no credit card required and no limits. You can talk as long as you like. You can also do free conference calls from your mobile with up to 5 other people at once -- this can be with people in the same city or with people in various countries all over the world. The company is based out of Toronto, Canada, and they currently offer 26 countries, with more on the way. Visit their site to start making your free calls today.
You can also start from your cell phone by going to their mobile site, which is free.talkster.com