if your looking to control electrical circuits tc then there are rc switch units available i know electronize do some and so do hunter systems.
basically a relay unit controlled via the Rx output they are limited in their control side ( depending on make about 3 amps).
havce a look on ebay
http://cgi.ebay.co.uk/SUBMARINE-BOAT...QQcmdZViewItem
this is the sort of thing.
alternatively on a budget , a servo with a long`ish arm on it and micro switch`s placed aorund teh arc of the arm , as the arm go`s past then the switch gets triggered and function becomes live.
there are otherways, but theyre the main types.
Adz..