Viber is the product of a small Israeli startup, Viber Media Inc. They launched the first version of their VoIP app back in December of last year to rave reviews.
Much like Skype, Viber makes free phone calls over Wi-Fi and 3G to other users with the Viber client. Unlike Skype, there's no need to create an account.
The typical process for making calls with 3rd party applications can be tedious. Signing up for accounts, verifying email address, and setting up contact lists are usually involved when using Skype or similar services. Viber made some waves with their no-username policy, and is set to do so again with the app's latest update...