Update 1: In order to animate this, you'll have to add a "new in event" on the "# Particles" operator. Just like this: http://goo.gl/rh9Gdp
Without it, pflow will multiply the number of particles by itself on each integration step creating almost an infinite amount of particles.
Update 2: Using more complex meshes, like a Chamfer Box, you can notice some render issues. Just change the Render Operator from Single Mesh to Multiple Meshes and it might work fine.
Based on Lee Griggs' idea, we'll create some abstract composition with hundreds of thousands of Boxes.