TONYB212  This is an excellent little programme! Once the airport connects the VPN starts up automatically in 3 seconds flat - very useful automation.  
(Version 0.2.1)

ALVERYX  Very simple but useful program that does what it's designed for. Easy to set up, sits in the Preferences pane out of the way. It connects as soon as you're on the network of choice.

Once thing that could be improved is that I wish it would reconnect automatically in case the signal drops out and then comes back into range, but otherwise it's good enough.

Works on my Macbook.  
(Version 0.1)