http://www.youtube.com/watch?v=x4JpwhXcivY
JTones has introduced TimeCore a $30 polyphonic arpeggiator for Windows that converts chords into midi patterns in realtime.
Using its matrix of buttons and velocity sliders, you can quickly build complex patterns.
Timecore was built for synthesizers but it can be used with any other VSTi instrument.
via Jtonesdirector