How to avoid Internet Disconnection while connected to VPN on Ubuntu or any other OS

I wished to have that feature since a very long time ago and at last I found a solution which was very simple! The solution idea is simple: Don't use your base OS to connect to the VPN, use a virtual machine instead, for example I use Virtualbox as my virtualization software and I have Ubuntu 9.04 as my base OS and Ubuntu 9.10 as my guest OS, I installed the Cisco-compatible vpnc and network-manager-vpnc packages, and then connected to the VPN on the guest OS and everything worked like a charm! On my base OS I can do everything I want as if I'm not connected to any VPN and my guest OS connects to the VPN and has access to all network resources there, simple, isn't it :) ?

Update: I did the same with a Windows XP guest and Cisco VPN client and it worked fine as expected.