No visuals for music through headphones – Audiogasm: Music Visualizer - Real time animation of audio and music for iPhone, iPod touch, and iPad Review

If you want some visuals for your music while you're using headphones, you're SOL. It only visualizes audio input via microphone.
Review by A6Trinity on Audiogasm: Music Visualizer - Real time animation of audio and music for iPhone, iPod touch, and iPad.