Unfortunately you simply need Lion or Mountain Lion to access these features on your desktop "mac applications".
However! Mail, contacts, calender & reminders, notes, find my iPhone and iWork documents synced with iCloud from an iOS device can currently (and presumably in the future too) be accesed at icloud.com from any browser with scripting enabled.
I do not have an @me or mobile me account myself. So you'll have to login and see if its already set up for you automatically, I assume there is no reason why it wouldn't be, as the mail server is already with Apple.
Other iOS devices that are associated with your Apple ID by activating "Automatic Downloads" which in laymens terms is Apples' iTunes in the Cloud service can have up to 10 devices (max of 5 computers) that will automatically synce iTunes Purchases including Music, Apps and iBooks to all those devices straight from an internet connection without the need for an iTunes sync. But iTunes in the Cloud will not automatically push TV Shows, Movies or Music Videos.
iCloud will also sync everything mentioned before about icloud.com, including Bookmarks and Photo Stream if selected, to any iOS devices setup with iCloud.
I hope that makes sense, for more information on how to setup a device with iCloud read this
Any more questions dont hesitate to ask :]
Message was edited by: itsJash
