I used the suggested script to bridge from OpenVPN and it took my client's server off-line!  Don't ever use their "sample" scripts if you don't have another way of accessing the server than SSH.

I actually found it easier to use iptables to tell it to route IPs based on a certain subnet to route through eth0:

iptables -t nat -A POSTROUTING -s 192.168.200.0/24 -o eth0 -j MASQUERADE

Replace "192.168.200.0/24" with your subnet of course.