Yoomba is an Isreali startup firm that is integrating e-mail with VOIP. It practically converts your email address into a phone or messenger, allowing users to talk to people around the world, for free. Its only PC-to-PC voip application but on the up side it let you call your contacts directly from any e-mail application that you are using. Since most of us check our e-mails regularly integrating e-mail and voip seems a practical solution.
Yoomba works with any e-mail application such as yahoo, hotmail or gmail. Very easy to setup up and use. On Yoomba website enter your e-mail address to register, you will receive an activation e-mail, click on the activation code and yoomba plugin download will start and install automatically.