I posted this earlier in the GPO forums, but thought people here might be interested as well.
I've been developing a MIDI visualization application that might interest some people here to make instant groovy music videos of your tunes. It's highly customizable, allowing different styles, colors, and behavior on each track, and will synchronize a MIDI track with an audio track. Here's a little proof of concept video I uploaded to youtube:
http://www.youtube.com/watch?v=aqzkhi9EXCI - showing one style across all tracks, and a mirrored visual
And a second demo with a number of new options running: http://www.youtube.com/watch?v=ej-CtPVKsH0 - showing multiple styles (one for each section of an orchestra) with time scrolling
The videos show two of my works put through an early alpha build of my MidiSpark application. The Midi and audio files were both exported as they were from Sonar without any further tweaking. The program attaches and synchronizes the two files. The video is processed from the midi file as the audio plays. Honestly, the uploaded videos do not do this justice, compared to seeing it play in real-time.
My plan is for completely customizable visualizations for each track in the midi file, including size, shape, color, movement and transparency of each represented note, as well as various graphical machinations. All style concepts will also be controllable via note-on velocities and controller information.
It's still in alpha testing, but I may be looking for beta testers soon.