Particle Instance ID Accessibility

Intro:

Particles in Blender are pretty powerful, but to make them more individual it would be wonderful to have access to a particle instance id for individual particles within the particle system. Currently I have access to this functionality in the material shader nodes in the form of 'Object Info'. For instance. if I wish to change the color of each particle I need only connect 'Object Info - Random' to the 'Fac' input of a Color Ramp. Essentially I would like to do the same outside of the material.

More Specifically:

Ultimately I would like to input a variable (integer or float) into the driver of a modifier (in this case the Frame Start of a Mesh Cache) to change the appearance of particles on an individual basis.

The result in my particular situation, will be a more seamless crowd simulation with less repetition. Because even if you create 5 different start times on 10 different animations and let that chug a render, when they're repeated 500 times they're noticeable.