Fedora 7 (fc7) Instructions:
Instead of uml use openvpn:
chown root.vboxusers /dev/net/tun chmod g+rw /dev/net/tun
Then:
You might need to make tiny adjustments to the eth1 script...edit yours (probably eth0 instead of eth1 also)
/etc/sysconfig/network-scripts/ifcfg-br0:
DEVICE=br0 TYPE=Bridge BOOTPROTO=dhcp ONBOOT=yes
/etc/sysconfig/network-scripts/ifcfg-eth1:
# Broadcom Corporation NetXtreme BCM5754 Gigabit Ethernet PCI Express DEVICE=eth1 BRIDGE=br0 HWADDR=00:1A:A0:B0:AC:9F ONBOOT=yes TYPE=Ethernet USERCTL=no IPV6INIT=no PEERDNS=yes
Then:
services network restart
openvpn --mktun --dev tap0 ifconfig tap0 up brctl addif br0 tap0
Then in virtualbox, set the network to host and set the interface to tap0. no scripts needed, but you'll have to figure out where to put the last three lines above to run automatically if you don't make a script.
Note that this is on the VirtualBox-OSE 1.4 edition on x86-64.