
It seems like forever since Apple/AT&T (whomever actually has control over that) started allowing VOIP over 3G back in October of last year and for the past 8 months Skype has failed to update their app to allow 3G voice calling. Until today.
Skype has released version 2.0 of its iPhone app (itunes link) and it makes calls over 3G. What's more, they sound great, as good as normal calls over AT&T's network. Maybe it's time to get the smallest AT&T plan, pick up Skype's $2.99 unlimited US and Canada plan, and save a bunch of cash.
Skype-to-Skype calling over 3G is currently free (it has always been free on the desktop client) but unfortunately Skype plans on charging for that feature sometime in the future for the iPhone


Free Skype trial
You've got until at least August 2010 to make and receive free Skype-to-Skpe calls over your mobile network.
After that, you'll need a mobile subscription
You've got until at least August 2010 to make and receive free Skype-to-Skpe calls over your mobile network.
After that, you'll need a mobile subscription