Is there a way to visualize music from the microphone? With all the media and 3D graphics capabilities available on modern hardware I'd like to see a nice visualisation application that listens to the microphone. 

If anyone knows the G-Force winamp plugin they know what I'm talking about.
Some 3rd-party apps can do this, such as:

Spectral Audio Analyzer

Free real-time audio analyser with 8 kHz spectral bandwidth. Display any sort of audio from the microphone as a coloured spectrogram. Identify environmental noise, search for annoying tones, view harmonic patterns of instruments and voices, analyse the frequency range of your speaker... .