There is a cheap alternative which I use to make international calls. I'm really happy with the services and thought I'd share it with you all.
I don't think it's available outside of Europe, but maybe if someone finds it of interest to their company, they can look further into it.
The service is called voipbuster.com. I pay 10 euros every 4 months and can call free internationally. It's really nice when I get off the phone with my mom in Canada after 2 hours of talking

and seeing that the remaining amount on my account has not changed. You only pay to call mobile phone numbers for few countries, and sending text messages costs 5 cents for each message. I can also add my house line and mobile to my voipbuster account so I can call free with them as well, and not having to be tied up to my computer.
There are only two downsides to the service,
no inbound number for my area ( Amsterdam) - but they are working on it and when you call someone, it shows up as private, but the positives definetly outweight the negatives.
I would love to hear what kind of alternatives others use then having a plan through local telcom provider.
Susan