Add A Second Line To Your iPhone With Line2
There are already some solutions to place and receive calls on your iPhone without going through your carrier or by using call forwarding. Google Voice, for example, does a good job at that despite lacking a native app, and we're all waiting for Skype over 3G. Let's face it though, those aren't really integrated all-in-one solutions.
Line2, by the VoIP provider Toktumi, tries to address exactly that. It basically provides you with a second, full-featured phone-line on your iPhone that you can use to place and receive calls as you wish using both VoIP and call forwarding.
After picking a phone number at the first launch, Line2 looks actually very much like the iPhone's native phone app. It has the keypad, your contacts, a visual voicemail, call history and even a whole bunch of setting to forward and filter calls.
It works over 3G, and while your incoming calls will be forwarded to your first (US) line when the app is off, we're hearing that a Push Notification system is in the works which will give anybody the possibility of having a true US phone line from anywhere in the world.
The app is priced at $1 and comes with a free 30 day trial. After that it will cost you about $15 for the service including unlimited US/Canada calling.
In short: Line2 is Google Voice + Skype over 3G, packed in a native app, for $15/month and it's making Apple look really bad about rejecting Google Voice.
Interested?