I'm researching this as a security experiment for a college related project. I would like to have VirtualBox running a system such as Pfsense, IPcop, OpenBSD, or some other good OS dedicated to security as a kind Super Firewall. I figure this should run in Bridged so the computer could work on a main network. The second half of this I'm not quite sure how to do. I would want the Host to turn off the direct connection to the NIC card and instead connect to the Virtual Machine Firewall. This way the VM would be a big security buffer between the Host and the outside network. If it was hacked, than maybe the VM would be taken out which would cause the connection to the Host to be lost. Also, if the VM was compromised, it could be restored with a Snapshot.