As Mike reported earlier today, Fring is launching a downloadable app for the iPhone that will allow people to make Skype and other VoIP calls over the data connection instead of using up talk minutes. Fring supports Skype, MSN Messenger, Google Talk, ICQ, SIP, Twitter, Yahoo and AIM services.

It is now live. (Warning: You will need to Jailbreak your iPhone to make it work). The Fring blog has more details or you can download it at the Fringcubator. With so many minutes on most cell phone plans, most people won’t be using this to make local calls. But it could come in handy for international calls or simply keeping up with IM on the go. The latter is really the killer app.