Windows 7 Tip: 
You can now make free calls on your iPod Touch. That’s right, we said iPod Touch! And free! The MP3 player can be transformed into a mobile phone with the help of a free application from Internet telephone company Truphone.
The Truphone application allows users with a Wi-Fi connection to make and receive phone calls via voice over Internet Protocol, or VoIP, with other iPod Touch owners, users of the Google Talk’s messaging service, and customers of Truphone’s Internet telephone service. The company said it expects to add the ability to handle landline calls.
The app creates a virtual keyboard on the second-generation iPod Touch to dial calls, and requires the addition of a headset and microphone.
Truphone for the iPod Touch is free to download from the iTunes App Store and once you’ve installed it all you need to start making free calls on your iPod Touch is a headset with microphone and headphones, which you can buy at electronic retailers or the Apple Store.
this is really cool