Hi, There is now a new Cell phone switch availble that you can Now Plug straight into a Mains Socket and the Plug your Electric Fenncet Into using a Universal Socket.
On Call can Switch the Energisor OFF and another Telephone Call can Switch the Electric Fencer back On
Alternatively you can operate the system via S,M.S
Comes a complete system including plugs and leads and the web site link is http://www.gsmswitch.com
Cost is approximently under 100 USD
Hope this is usefull as the system has many other applications for controlling electric devices around the farm and can handle up to 18 Amps A.C
As of 1/23/14, the link is dead. Anyone have an updated one? I'm all for open source and DIY, but I also like simple and working. The cost of the parts for Rover is comparable to this device. Very interesting.