Using more than one computer, often it would be useful to have a way to synchronize settings among multiple computers. For example you change the desktop wallpaper on your office PC and you want to find the same wallpaper when you go back home on your personal PC or on your laptop. Language settings, online accounts, privacy settings ecc... are only few examples of settings you could want to have synchronized.
Ubuntu One already gives you 5 Gb space for free and it's available for everyone activating it. It's a perfect place for storing a shared folder with all those settings. Of course not a simple folder, a special one. Applications use settings taken from usual \~/.appName and a daemon takes care of synchronizing data once you're connected to Internet. Just like Ubuntu One does with your documents.
How do I choose which settings to synchronize? First of all you have to activate an Ubuntu One account, if you don't have already done it, then you just have to choose the settings you want using this tool available in Ubuntu System Settings
What? A mockup?! Isn't this tool available yet??!! Exactly :) This tool is not available yet, but I think it would be an interesting feature to talk about for the next (not precise, I mean 12.10) Ubuntu release. What do you think about?