All this talk about Google's Chrome OS has made me think a bit.
While in general I agree with both Dion Moult and Christian Weilbach and am in general mistrusting to cloud computing (at least in its currently most popular form), there is something else that bothers me with this hype.
As of late a lot of talk and effort about cloud computing was being done in the direction of making it work on netbooks and similar mobile devices. To me this makes no sense! Having your documents and data online is a great idea if you have no computer of your own or you have to migrate a lot, but only have a stationary system.
But if you can take all your data with yourself on a ultra-portable device with hours of autonomy time (e.g. netbook, smartphone), why would you rather have it online out of your direct reach? It is neither practical, because you need a network connection all the time, nor does it spare you much diskspace (if we completely ignore the "intellectual property" and privacy complications). Yes, SSD's are still small, but frankly, all that music and movies take up a lot more space then your calendars, inbox and documents put together!
There are cases when clouds make sense. But it always depends on what they are used for and how they are implemented. For example, I am very happy with SpiderOak's encrypted and clouded backups and am looking forward to SocialDesktop if its done right (and it seems like it might be). I even have some insane ideas about binding together NEPOMUK with P2P and F2F technology. But I will write about all this some other time.