Jajah
There are no charges as long as both communicating users are registered with Jajah and have a local number in one of the six countries. Calls outside of these six countries carry a charge. charges are listed on the site.
Here is how it works:
1) go to http://www.jajah.com and register.
Make sure the person you want to call is also a jajah member.
All you need is a landline or handphone number and an email address.
2) Key in your phone number and your recipient's phone number on the Jajah website and you will be connected.
Voice quality is a tad inconsistent but you get what you pay for or don't pay for. Still, worth a try.