iCall has a closed beta of their system for the iPhone in work.

iCall allows you to route your incoming cellular network calls to your iPhone via VoIP when you are connected to a WiFi hotspot. You can also send and receive VoIP calls over WiFi.

Watch the demonstration video for more information.

Godzilla-like Japanese telco NTT DoCoMo has reared up from Tokyo bay to offer it’s customers wireless telecoms connectivity for their mobile handsets via their home broadband.

DoCoMo FOMA handsets which have WiFi connectivity will be able to utilise a new service called Home U which allows them to make their normal telephone connections via their home broadband rather than the cellular network. This will allow for free calls between Home U user when they are in their own residence. It will also allow handsets to download large volumes of data such as video at up to 54Mbps - this is a limitation of the WiFi technology, in fiber to the home areas, the actual speed of Japanese broadband is often 100Mbps.

Martin Sauter for WirelessMoves has written a brief article highlighting the risks of using unsecured VoIP services on public WiFi hotspots.

He points out that quite often, by default, your communications over a public WiFi hotspot are not encrypted and that goes for the voice stream too which could be passively lifted from the airwaves and replayed.

What do you talk about on your Voice over IP calls and would you be concerned if a third party knew?

Om Malik of GIGAOM has written an article about how he replaced his regular land-line based telephony with a voice over IP service from UK based Truphone.

Om uses Truphone with his WiFi equipped Nokia E61.

Photo Credit: Ryan Sinn cc-by-sa-3.0

Phone Boy Blog has an article detailing his three major gripes with using VoIP on mobile phones (within the USA)

His biggest gripe appears to be that there are no cost savings available presumably due to the cost of data plans.

I’d also probably add to his list to include potential communication interception vulnerabilities when using WiFi enabled phones on open hotspots.