This is a quick overview of using the Combinator in Reason 4.
You may also want to check out the video below, which looks at Combinator Modulation Routing in Reason 4, and the resources listed below.
iPhone Control Of The Reason Combinator
Using the OSC tools for a non-jailbroken iphone to trigger combinator effects in Reason 4.0. This relies on OSCulator, the application popularly used for the Wiimote interface, and the OSCemote iPhone application.
Reason Combinator Resources: