[Update: Sony, other media companies upset by early announcement] Amazon in the night unveiled its rumored media locker and beat Apple and Google in the process. Cloud Drive gives users a way to store a minimum of 5GB of files on the web and access them from any Mac or PC. The company has a unique tie-in with Amazon MP3: any songs bought through the music store are saved to the Cloud Drive and available either for backup or for remote streaming without counting towards the quota.