Using your cell phone to call with any Voip Provider, saving on your phone bill... that's Fring, a cool free tiny application that runs on many mobile phone operating system, and allows you to load your buddy lists from Skype, Google, Msn, ICQ, and many others, including SIP providers.
By the way, you can also chat through instant messaging, bringing your contacts with you wherever you go.
Fringsters (Fring users) can do free mVoIP calls and chats when using free Wi-Fi internet access or fixed internet data
plans with their mobile phones. Isn't it great?