Note: this post is from 2006, outbound links may be broken.
CacoFX releases ChordME v1.0
CacoFX has released ChordME, a freeware midi VST that converts incoming midi notes into full chords.
Different chords can be assigned to each note across the octave so that complex chord patterns can quickly be built up from simple midi lines.
It can also transpose the generated chords or the original midi notes up or down octaves.