Using OpenVPN to Manage Multisourced Infrastructure

Saw this article when looking for information on using OpenVPN with Amazon Web Services.  It is not exactly what I am looking to do with my latest project.  But it is some good helpful information for those with existing infrastructure looking to use AWS.  There is also VPN-Cubed which is another option if looking for a supported product.  I have not used it but would love to hear some comments by those who have.