According to to this article "ICall Inc.'s planned iPhone application is still in beta testing. Like Truphone's app, it will use wifi links to access the VoIP network. A unique feature is the app's ability to switch from a cellular call to a wifi call without interrupting the conversation. ICall claims that such transfers will happen "seamlessly." CEO Arlo Gilbert said that the application should be available in early August 2008." I should also note that they wont charge for calls like Truphone's http://www.voip-news.com/feature/iphone-voip-apps-roundup-071708/ Edit: The article discusses other VoIP options too. Here's the website: http://icall.com/iphone/ I just hope Apple lets them through.