Macworld UK reports that Apple’s iPhone will be able to make voice over IP (VoIP) calls using a mobile web tool that works via smartphones’ built-in web browsers.

It seems Jajah's Mobile Web service will allow iPhone and smartphone owners to make these calls without users needing to download any software.

All an iPhone user will need to do is type the address into their browser, and then enter their user name and password in order to be able to call people from within the browser.

More here.