Truphone, a UK-based company, has released a VoIP application that will enable the iPod Touch to function as a Wi-Fi phone. The calls will be carried over the Wi-Fi network with the help of a microphone adaptor and will allow Truphone Touch users to call on landline and mobile phones as well as receive calls from them.
Apart from lower call rates, Truphone will allow free calls to other Truphone users as well as free calling and instant messaging with Google Talk, Skype and MSN users. Twitter and Facebook support also make a nice addition.
You can download Truphone application for iPod Touch from here.