Amazon has launched a new tablet computer called the Kindle Fire to rival Apple's unusually successful I-PAD. Many rivals are trying to emulate the success of Apple's I-Pad with look-alike tablet devices, but none has come close. Amazon's Kindle Fire is seen as a chance because it is much cheaper. Amazon will be hoping to leverage both the strength of the Kindle brand, built up over three generations of its popular e-book reader, and its ability to serve up content such as music and video.