Viber - for the next time Skype goes on the blink
In the past 24 hours, Skype has suffered an unusually long outage, forcing users across the world to curse under their breath and find alternative products for instant messaging and free phone calls.
Another one to throw into the pot is a new iPhone app called Viber. It's a free app, and means free calls to anyone else using the app via 3G or WiFi. Unlike a lot of similar apps, Viber uses push notifications to alert a user to an incoming call - there's no need for the app to be open at both ends to place calls.