Jajah offers a very simple way to make phone calls using the Internet without headphones, microphones or having to install any software - it connects two phone lines using the internet. And since Jajah webphone client is web based, the VoIP service can work on any platform.
Users go to Jajah's website and enter their own number and the one to be called. The company rings the caller's number, and after the user picks up, it dials the other number. If the call is answered, Jajah connects the two lines.
Jajah breaks voice calls into data packets just like e-mail, sending them over the Internet and reassembling them into sound at the recipient's end.
The call goes from phone to phone, with Jajah's site and the Internet as the intermediary. Domestic U.S. calls cost about 1.7 cents a minute. A U.S.-France call costs 1.9 cents.
Watch Jajah in action (Google Video)
Make a phone call with Jajah
Source: Yahoo News