Ever felt nostalgic about the good-old Winamp-style visualizers like MilkDrop? Good news: the guys at Vidvox made a free, Syphon-enabled app based on "projectM", which is an OpenGL-based re-implementation of the class MilkDrop engine.
ProjectMilkSyphon can be used to create sound reactive visuals from an audio input to your computer such as a built-in microphone or line in **and mixed into your favorite VJ apps over Syphon."
There are a couple of options, like selecting the audio source, gain, but this little app can even trigger and fade between the hundreds of built-in visualizer presets - and its awesome!
ProjectMilkSyphon has built-in Syphon output, so you can feed CoGe by it's output pretty easily – just create a SyphonSource in CoGe, and you are ready to go!
Download free here: ProjectMilkSyphon