Hi, here is a new Max for Live device: the Granular Stereo Faker.
It is a subtle granular delay: the different delays between right and left channel create the stereo effect.
This is more audio FX than a stereo enhancer, but I use it a lot, to give life to static mono sounds.
Granula Stereo Faker is FREE here!More info
And here is a video of the Granular Stereo Faker in action: