I recall, when I bought my black MacBook a few years back, mentally shaking my fist at the sky and crying "Curse you Steve Jobs!!" as the camera crash-zoomed into my face. I was cursing Mr. Jobs because, despite it all, I paid the Black Tax. Similarly I'm starting to have this sneaking suspicion that, one day, in spite of myself, I'll pay the Thin Tax that was introduced to supplement the Black Tax.
I've been a two-machine guy for over a year and a half now. When I first had my MacBook Pro and the Mac Pro, I decided that the way to deal with this was not to sync, but just to decide what each machine was for and stick to that demarcation.
The Mac Pro had two drives: one for "media" - photo and video editing - and one for development. The laptop had business documents, email, web, RSS, blogging and iTunes.
A fair amount of that already lives in the cloud: IMAP for mail, Google Reader for RSS, .Mac sync has been working well for me with bookmarks, and MarsEdit does a decent job of being used from two places.
I audited all the other data on my laptop, and the results were surprising:
Yes, that tiny little fraction of a stump of a bar is all 850MB of all the data I have ever generated that is otherwise not managed for me.
The source code I care about lives in Subversion and can easily be used from any machine. The photos are only there so I can show slideshows from my laptop and that, really, lives in the cloud too on Flickr - at least the good ones. System, Apps and Dev Tools are what they are and one can't change them.
iTunes can move to the desktop no problem. If I want tunes with me, I have the iPhone. I also have an 80GB iPod left over from that portion of my life before the iPhone came. If I want the entire library with me (say, a big trip), I can just take along the big iPod. I see no reason why this isn't a sustainable approach. I'm sure there will always be a "big" iPod somewhere in Apple's lineup and it's not as if there aren't bare mobile hard drives that cost about the same as an HDD-based iPod. If the main reason for owning a big iPod is as a slim way to carry your entire iTunes library away from home, I don't see that paying £160 every few years is a huge problem when you get an iPod thrown in too. After all, if it was mainly a media storage device in your setup, you wouldn't be upgrading it at every revision either.
So that leaves 850MB of things I'll want to drag around with me. The answer? iDisk. I've been living from a sync'ed iDisk for a week or so, and it's been great so far. I have some experience with MirrorAgent from administering Mac OS X Server at work, and I understand that the iDisk sync is the same technology. The iDisk experience as a pure WebDAV mount is pretty poor (especially on Tiger, it seems) but the synchronised iDisk has been working great for me so far.
The only thing I have left that I want to get everywhere is my 500MB Yojimbo library. In principle, I can sync that with .Mac but I've never had success with that in the past, and I'm a bit nervous to try.