Maybe you could set a translucent menu bar, then script something to change the top 22px of the desktop background based on the VPN connection status. It's hacky, but it'd work.
Another option would be to configure your routes. At a previous job, I set up my home router to connect to the VPN and route 10.* to the VPN interface. Setting this up isn't easy, but it's oh-so-convenient. Reading http://wiki.openwrt.org/doc/howto/vpn.client.pptp will start you on the right track.
Be careful though. This gives anyone on your home network access to work. It almost certainly violates security policy. I only did this because I knew I'd just be chastised if I got caught. (Same goes for running rogue APs at work.)
Another option would be to configure your routes. At a previous job, I set up my home router to connect to the VPN and route 10.* to the VPN interface. Setting this up isn't easy, but it's oh-so-convenient. Reading http://wiki.openwrt.org/doc/howto/vpn.client.pptp will start you on the right track.
Be careful though. This gives anyone on your home network access to work. It almost certainly violates security policy. I only did this because I knew I'd just be chastised if I got caught. (Same goes for running rogue APs at work.)