For the other 50% of smartphone users that are on Android (as per this http://news.ycombinator.com/item?id=2855717 http://news.ycombinator.com/item?id=2855717 )

For the other 50% of smartphone users that are on Android (as per this http://news.ycombinator.com/item?id=2855717 http://news.ycombinator.com/item?id=2855717 ): you can use OpenVPN and certificate authentication, Cyanogenmod supports it natively. Tunnelblick is the OSX client of choice for OpenVPN.