I've been meaning to do a followup post on N900/Maemo5, but every time I summon the effort to start drafting the post, a new firmware comes out to address problems motivating the post. Case in point: the most recent firmware (PR1.2) finally added the USSD code support one needs to query Tmobile about money left on prepaid accounts (a fantastic money saver for me).
But one thing that has become readily apparent is why people are so excited about "the cloud". Roughly speaking, the non-technical and semi-technical people who use that term mean something other than elastic computing. As best I can tell, what they're after is an online datastore / network API that's on 24/7. Which can be neat, but isn't the revolutionary thing you might imagine based on the rhetoric.
Anyways, about that neatness: after a few months of smartphone ownership it became apparent that I need some way to deal with the fact that all of my devices create and store new data sources, but none of them are on and accessible 24/7. Solutions like unison remain academic because they are neither automated nor available 24/7. Essentially, it seems people are rediscovering the value of mainframe computing, but with redundancy and graceful degradation to offline mode. Maemo5 meets this concept to varying degrees of success.
Synchronizing music libraries is relatively simple, and even Banshee supports it. Simple file sync tools like unison are also admissible to me because generally speaking, I don't add much music very fast and changes needed immediately. But there's a side problem here: hidden data. Music ratings are a great tool I use to create shuffle playlists of minimally acceptable music. Because the MP3 format does not include this admittedly subjective rating field, it's not sufficient to sync files to get this data. It's become clear that the tight integration iTunes offers by sharing metadata between desktop and device is pretty damn useful. Granted, they're impossible to get out, and people sometimes accidentally wipe their ratings stored on iPods, so perhaps the grass is just greener on the other side of the electric fence. Perhaps I should see if something like Last.fm / Libre.fm can play a role in collecting and syncing this data.
Maemo5's media player doesn't provide a rating concept, so there's nowhere for this data to be put on the device for smart playlists. I hear that Meego took a great step in the right direction by selecting Banshee as the media player, so I hope the group takes time to address Banshee<->Banshee setting sync, to meet or beat iTunes.
Maemo does an outstanding job here with a great idea. The unit of software deployment on smartphones is generally the app. Maemo's Sharing plugin system does a superlative job of modularizing the upload process such that you don't need a seperate uploader app for each hosting provider. There is a gallery2 plugin, which works well for me, and there's no shortage of other plugins if you prefer not to self host. This deserves an A++ and I hope Meego keeps this tradition.
Bookmarks / History
Upon seeing that Mozilla was building their mobile Fennec browser for N900, I decided to check out Mozilla Weave. It's a great replacement for an old tool that was popular and canceled before the term "cloud" was cool: Google Browser Sync. They've since rebranded it Mozilla Sync which maybe indicates more clearly what the product does. Many people use Xmarks, but Sync also handles history, preferences, even tabs. Mozilla offers a central service, but I prefer to use the minimal standalone system that I can host myself. This is probably the ideal -- people who want privacy have a number of steps they can take, while there's still an easy to use compliment. Interestingly, Meego has chosen Chrome as it's default browser, and the state of the art in cross browser sync is bookmarks only (I can't imagine sharing preferences between browsers being useful).
Calendar & Organizer
I've lately been experimenting with calendars and todo lists at work. For example, I have "package weave-minimal for Ubuntu" as a todo item. At work we have Exchange and Outlook. At home I have Evolution, which integrates with the desktop in some neat ways I'd like to keep. Surprisingly, Maemo supports Exchange very well. Calendars / alarms, todos, notes, etc. all come across fine, and PR1.2 even generates responses to meeting invites. Ideally, I'd keep work and personal data separate and let the phone unify them for presentation, but I've yet to find a way to do that -- CalDAV support is not in Maemo. The good news is that I've seen a few emails from Nokia developers that suggest CalDAV might work in Meego. Guess it's time to set up a personal CalDAV server and point Evolution at it.
As far as contacts go, I generally just centralize it on the SIM card and leave it there, but I think Ovi has a system in place, and syncML has rough support.
I don't know why this form of cloud computing is popular now, when many of the same problems and solutions have been around since laptops and wifi. Perhaps the pocketability and utility of cellphones cancels out the "nerd factor" associated with carrying around laptops, so that people now run into these problems daily rather than just during offsite business meetings. Either way, there's plenty of technology to support private cloud systems; I use gallery2, weave and (soon) CalDAV privately to synchronize my computers.
Frankly, the greatest remaining challenge I have left is storage. In contrast with jzawodny, S3 doesn't even come close to making economic sense at personal scales of a couple TB, and Dropbox is even more pricey with less data at end. For now I'll just take the availability risk of residential networking and save the money.