Following up on our story about VoIP on the iPod Touch, it seems that we now have the missing link software which will turn your iPod Touch or iPhone into a lean, mean VoIP calling machine.

fring, a mobile internet service, released its mobile software for the iPod Touch and iPhone on Apple’s App store this week. The interface enables VoIP calls over wifi on your mobile device using your Skype account as well as live chat with your MSN Messenger, Google Talk, Twitter, Yahoo, AIM and more.

The software has been available for download since last Spring for those willing to jailbreak their iPod Touch or iPhone and override Apple’s DRM. However, times have changed and Apple has opened both devices to 3rd party applications with the launch of their App store. Adding microphone support to the iPod Touch was the final piece which makes all of fring’s features now fully and “legally” functional on both devices.

Check it out in action on the iPhone…

The software is also available for many other mobile devices. See their download page for a complete list. They even offer a cool widget for bloggers wanting to talk/chat or maybe I should say “fring” with their readers.

Did I mention that fring is also free? It seems like this little gem is going for zero dollars for now. What do you think? Is the iPod Touch vying for best travel gadget ever now? I fringing think so.