Apple FaceTime is a revolutionary technology that lets you make video calls on iPhone 4. This technology is so popular not because of some video streaming or some other techniques Apple uses, but because of the ease at which you can make a video call. With a single click you can make video calls.
This technology was first introduced in iPhone 4, later rolled out to iPods and now to Apple Macs. In the recent event “Back to Mac” Apple announced FaceTime beta availability for OS X. With this it possible to establish Facetime call with almost all the devices of Apple ecosystem except iPad. iPads are expected to get FaceTime soon.
Here is the video of Steve Jobs demonstrating FaceTime on Macs