Abstract: You are one person, using multiple devices - why shouldn't your stuff follow YOU rather than the device? Since we don't like depending on a 3rd party, the "home" cloud is the answer?
Most programs today are isolated islands of functionality. The Web 2.0 transforms that, allowing you to mesh together pieces of functionality and information. The same is not true on personal computing platforms i.e. your laptop.
The bookmarks you store on your laptop can't be accessed when you're on the desktop at home and vice-versa. Same for your notes and pretty much anything, unless you manually copy them etc.
Option 1: store information on the web (centralised location). The one benefit of this is the ability to use that information from anywhere and any device. The drawbacks include big-brother and relying on a 3rd party for availability (including backup etc). Of course, the need to be online...although smart solutions can use local caches.
The big brother issue is getting worse. As much as you trust ALL levels of government of ALL countries that may have a claim on you or your property AND all their agencies, there are more and more corporations that mine all kinds of data about your person, for different reasons. Some as benign as offering you a new credit card and some as bad as credit recovery, setting insurance premiums etc. Let's not forget identity theft.
Option 2: use a home server. Basically, almost everyone has by now a server at home, which is constantly connected to the big Cloud, whether you're downloading movies or host your own blog. Why not use that instead of a 3rd party, to serve other stuff.
There are many a solutions to host your own stuff and access/share from/with the world. There's lots of software to serve security camera feeds, TV programs from your home, the Windows Home Server etc...the trend is already in place.
Having resolved (somewhat) the big brother and 3rd party dependency problem, there's still the issue of needing to be online.
Option 3: fully distributed and synchronised personal cloud. Store information locally, on the device that creates it (like on the work desktop where you save a favourite) and synchronise all devices (peer-to-peer or properly distributed solution). The only drawback is lack of on-demand availability of the information from other devices, until the sync occurs. This can be solved however by connecting your own PC to the net...or combining with option 1 or rather 2.
The vision is that of you and your information following you. In fact it's not following you...it's just "there" for you to use. Whatever computer in your "home" cloud you use, your information is there.
I mean, will you upload ALL your favourites on facebook, just so you have them available in the living room, when you get home? I don't think so!
The solution is the logical conclusion of the same debate of distributed vs. centralised that's been raging for the past few decades. All those "in the know" know that it's a wave function. Now we may be heading towards the climax of centralised internet based clouds, but, as more PERSONAL processing power becomes more online, split between more types of personal devices and connected, the trend in the other way is just a matter of time...wave, right?
So, I dream of many agents, running on many personal devices, connected in your "personal" or "home" cloud, sharing all kinds of information and cooperating.
So, when you mark a "favourite" on your work desktop, it automatically gets replicated on your laptop, your home desktop (the cloud's gateway) and all the computers in the house, including the one in the living-room. There's nothing left to do but, when you get home, sit down and enjoy it on the big screen!
No 3rd party knows you enjoy that hardcore woodworking show or that you're trying to fix the toilet seat, no insurance company can mine that you once watched 3 illegal races on youtube etc...all usually available on your facebook or whathaveyou.
-------------- The social aspect
Today, no application is complete without considering the social aspect. You could obviously push some of your favourites to facebook, or share with friends in "friend" clouds.
-------------- Flexibility, customisation
Probably the biggest gain from a "central" cloud, like gmail etc is flexibility and customisability. Gmail is gmail is gmail. That's exactly what it does and, while you may change it's fonts and even access it remotely via an IMAP or http API (thank you, Google) that's still exactly what it does.
A personal cloud, though, can be customised. You decide what it does and how it does it.
-------------- try it
If you want to play with such an agent, try a preview of mine, at http://razpub.googlecode.com/downloads
Read more about it at http://wiki.homecloud.ca
You can even try the remote favourites sharing prototype...follow this link after you downloaded, installed it and started it on several computers: http://localhost:4444/mutant/capture.html - After capturing, go to another computer in your home cloud and see the links at: http://localhost:4444/mutant/asset/Link
This is written as of version 0.x so the links may change - the use case however will be maintained up-to-date in the wiki, at http://wiki.homecloud.ca/savedlink