iCloud is a new addition to the roster of cloud-based operating systems, tools that allow you to store not just your files online but the applications you access them with.
We've talked about cloud operating systems before like EyeOS and Glide. iCloud shares webtop roots with them, bringing the experience of desktop computing to your web browser. Once you sign up for a free iCloud account you can get started immediately working within the virtual operating system. There are dozens of applications and widgets. You can edit documents in a Word compatible editor, maintain a calendar, and write emails. There is a photo organizer and media player that lets you listen to and share your music wherever you are. The Vista-like sidebar can be customised with a variety of widgets to suit your workspace—your first order of business will likely be to replace the "Last Users Online" widget with something more useful.
iCloud is currently in beta and while it lacks some of the meatier features found in previously reviewed webtops, it does provide a completely mobile and relatively distraction free work space. According to the iCloud team, iCloud is best suited for use in Internet Explorer. You can—and I did—use it in Firefox but support for Firefox is considered experimental. iCloud is a free service and requires Internet Explorer with Java Script installed.