Amazon S3 is Amazon Web Services' online storage service. Anyone can buy a nearly limitless amount of Web storage for pennies per GB. Many start-ups and Web services take advantage of S3's low prices and fairly stable uptime to take the place of having to host and store data themselves. While there have been a couple of hosting hiccups, it's remained up and running since its public launch in early 2006.
One of the things that makes S3 more attractive to start-ups and power users is that it ties in with other Amazon Web Services like the elastic computing cloud and its SimpleDB service. Using all three, start-ups can offload some of the tasks that usually required spending a large amount of money up front to do this work--saving them, and potentially their customers time and money.
Winner: Amazon S3 (Aws.Amazon.com)