“Sipcall, a Silicon Valley start-up, will offer a free Skype and SIP calling service dubbed Hipsip that enables users to make their voice-over-Internet calls from any mobile phone’s web browser.The interesting thing is that you don’t need a 3G data or WiFi wireless networking connection on the phone in order to do this. You could, for instance, use Hipsip to make a free Skype call on an Apple iPhone.This won’t make AT&T, Apple’s cell phone carrier happy. AT&T would rather earn revenue from you using its own voice plan. In any case, the calls made with Hipsip still require a local call. So AT&T gets those local phone call minutes, even if they are a mere pennies per minute. Overseas calls are normally far more expensive on a carrier’s network.A user installs the Hipsip application on a PC. Then he or she can open a browser on a mobile phone and go to the Hipsip site. There, the user can see his or her personal Skype contacts. To call a Skype contact from the mobile phone, the user can click on the name in the Skype directory.” – Dean Takahashi at VentureBeat
Source:http://venturebeat.com/2008/04/01/sipcalls-hipsip-offers-free-voip-calls-from-any-mobile-phone-browser/