I have more music on my desktop computer than will fit on my laptop's fairly small SSD.
Is there any way I can sync just some of it to my laptop, or do a kind of cached streaming like on Android?
I suppose I could choose to sync just particular folders for albums I currently like but that seems a bit tedious.
There's currently no Ubuntu One music streaming player for Ubuntu. It'd be nice if there were and you fancied a spare-time project, though :) Let me know if you're interested...
In case you have a Spotify Premium subscription, it automaticly syncs the playlists you choose for offline playback on your laptop (automaticly copying local files as well), as long as you have Spotify running on your desktop and laptop at the same time and are connected to the same network.
Not exactly what you asked for, but that's how I resolved the exact same problem :)