earlier this year I wrote about icloud. Since then things have moved on and iclouds have now launched a hosted service that's usable from a range of devices including the iPhone.
This is an intersting move as one of the problems with having multiple smart devices, computers, phones etc is that your stuff is well, everywhere. Services like Dropbox help keep individual stores in sync (as well as providing a silent source of information leakage).
The next stage is cloud based storage so that your stuff is accessible from everywhere. Doing it through a browser provides a universal access mechanism, and coupling this with virtual compute allows you to execute applications without worrying too much about local host architectures or capabilities - something that ajax heavy applications like google docs or wikidot do care about.
It's interesting - cheap host agnostic computing - all you need is a (recent) browser ....