A new application called iCall allows iPhone owners to place VoIP calls over WiFi networks.

ivall actually does more than just place and receive VoIP calls. iCsll can also switch incoming calls over to VoIP before you answer. The company behind the application (also called iCall) provides free VoIP services, so presumably you'll need to sign up with them if you want to place calls over WiFi. Either way, the application sounds pretty good to me, since my WiFi signal at home is quite a bit stronger than my GSM (cellular) signal.

The fact that oCall exists is good, but the fact that it's being developed as part of the iPhome Developer Program is even better, since the application will be available to all iPhone users. The team also claims that the application is programmed using only the tools provided in the SDK. That's also a good thing, because it means that other developers should be able to come along and write VoIP applications for Vonnage, Skipe, and any other service without too much trouble.