Facebook provides a great way to keep in touch with people all over the world, including an instant messaging service. Text and images are all well and good, but there is no real replacement for talking to someone.
Vonage Mobile for Facebook enables you to make free phone calls to your Facebook contacts - the app is all that’s required so you will be able to chat with any of your friends who have downloaded Vonage Mobile.
The app can be used over wifi and 3G connections, so it is a genuine replacement for standard phone calls - the app itself is free and is guaranteed to save you money very quickly.
Support for iOS 4's multitasking means that there is no need to have the program running in the foreground in order to receive calls.