Last week's mac techmail was How to set up an OS X OpenVPN client which looks at using the fantastic Shimo VPN client program to setup a client endpoint to an OpenVPN-based VPN (using certificates). It ties in with the other tips in this "series" regarding OpenVPN.
Shimo is quite awesome. I use it with a few different OpenVPN VPNs and have used it with Cisco VPN as well. Highly recommended application.