Not sure if this is what you mean by syncing, but I have been trying to use my Zaurus as a net enabled "window" into a more powerful enviroment, based on a linux server and my OS X based client at home. The major bonus of the zaurus is the flexibilty of using web based apps, X based apps and common file formats (Lyx is a favourite!)
The most important things for me are:
- the size (pouchable/pocketable)
- network transparency (ie: being able to connect anywhere at max speed)
- good suspend/resume - pdaXrom is pretty good with this
How do I manage data? Well, I run an IMAP mail server, an iCal based calendar server (shich I sync with kopi) and VNC. I also run ftp over https. Oh, and I use Zwiki with WYSIWYG interface compatible with thunderbird.
This allows me to use the SAME DATA behind corporate firewalls etc.. So that if I have access to a fast client/network, I can leverage it's power but the syncing of data is simplified.
How do I connect? I use bluetooth and a 3G phone as a modem - $30 a month for 100MB, $50 month for 300MB. and it's fats enough for VOIP etc... At home I use wifi.
Personally, I hate laptops, anything that requires a separate bag, can't be pulled out on the fly and needs a power source after a couple of hours is NOT portable!
By portable, I mean something that you can take with you or a week anywhere (overseas, camping etc), doesn't weigh you down and can get connectivity in a variety of locations.
I quite like the watch idea, but even a bluetooth remote is probably enough, something that can resume the device and be used as a basic interface - (how about "read my new mail" - text to speech engine!)
Anyway, diverging here...