Note: Modul8 will have Syphon input from version 2.7. If you own a Modul8 licence you can download the 2.7 beta from your GarageCube user space. Native Syphon input will render this tutorial useless.
While waiting for Modul8 to get real Syphon input you can use this method to achieve it.
The files you need to make this work could be found on these sites:
QC Rehab plugin at Kineme.net
Syphon plugins