Apple’s Steve Jobs made an appearance Monday at the Worldwide Developer’s Conference despite being on medical leave to help announce the creation of Apple’s new iCloud service.

Walking out to a standing ovation after the loudspeakers played James Brown’s ‘I Feel Good’, Jobs stayed on stage only minutes before he turned it over to marketing chief Phil Schiller. That did not mean Jobs was finished.

He returned later in the presentation to talk about the new iCloud service, which he did with much animation. The service will be free for users and will offer many benefits that the company hopes will compete with the likes of Amazon and their cloud storage. According to Jobs, users that set up an iCloud account will be able to store data from multiple devices on one server that can be accessed from any device.

The data will be stored and backed up on Apple servers so that no data is lost and so that it is accessible at all times from any device. This means users can access all of their contacts, files and calendar information regardless of which device they are using. It will also allow them to store and access their music online.The new iCloud service will make it so that users no longer have to transfer songs using their home PC.

In addition to the iCloud service, Apple had some other new introductions at WWDC. They unveiled the update for the Mac operating system known as Lion. Apple also told of the update to the software currently used on iPads and iPhones. Lion will be available next month and iOS5 for iPhone and iPad will be available in the fall.