I've been using PortableApps for a while as a way to keep a copy of FileZilla and Firefox close to hand with my preferred settings.
Like most PortableApps users I used to use a USB key to carry them around - but recently I've been less attached to that dongle and started relying on the cloud storage and synchronization capabilities of Live Mesh to make sure the utilities are always to hand.
Because PortableApps doesn't install anything on the host PC (it's more like an OSX or Linux app in that regard - no registry changes, no INI files squirreled away in user directories) it's a perfect fit for a Mesh folder... and really easy to set up.
I created a new Mesh folder on my test machine and called it PortableApps (imaginative I know, but I wanted to be able to find it easily!). I then installed the base PortableApps version ("Platform Only") into that folder to get everything initialized. Once that was installed I added the three apps I wanted - Filezilla, Firefox and the PortableApps updater (useful to keep things at the latest version - no Windows Update for these apps sadly!) and tested they were working.
Just for good measure I added a shortcut for the Portable Apps launcher to my Windows start folder so it would run automatically when I logged in.
I then sync'd the folder to machines where I knew I wanted to run those apps (my Windows Home Server and my laptop) and also shared the folder with my wifes Mesh so that I would always have the apps there if I was using her machine for anything.
Now my settings follow me around, and if I update something on one machine a sync later it's everywhere I need it.
... is this the start of everything living in the cloud and being available on every connected device I can authenticate on?