iCloud is Apple’s MobileMe replacement, which so far has little to recommend it besides a) backing up your iOS data automatically and b) being free (up to a point).

So far, the document synchronization bits have failed spectacularly for me (even leading to some data loss), so I’m not trusting it beyond contact and calendar sync.

Apropos nothing, here is an SVG rendition of the standalone cloud that you can use as a basis for further artwork.