A geek's day: I've set up a guest WLAN network on a router, which is isolated from my default WLAN network. On the ownCloud front, I've set up external storage in my ownCloud instance; the instance sees it as a local directory, but actually it is a hard disk drive at my apartment, mounted on the router, connected via OpenVPN to the server where the ownCloud insetance is, and then mounted to the server through NFS.