The Cheerio Effect

Most days (ifI wake up in time), I like to enjoy a breakfast of Honey Nut Cheerios. With Honey Nut Cheerios, as with many other breakfast cereals, a curious phenomenon occurs when the cheerios float in milk (unless you are one of the few that consume cereal without milk, with which I have no response other than sadness). I'm sure many of you are well-acquainted with this so-called "Cheerio" effect, at least qualitatively. It goes something like this:

When cheerios float in milk, they tend to aggregate together into large clumps. The effect is visibly akin to objects gravitationally attracting each other to form a mega-clump.

Today I wondered whether anyone had analyzed this system quantitatively, and lo and behold, a scientific paper on the "Cheerio" effect:
http://people.maths.ox.ac.uk/vella/Vella2005.pdf

Here's the abstract:
Objects that float at the interface between a liquid and a gas interact because of interfacial deformation and the effect of gravity. We highlight the crucial role of buoyancy in this interaction, which, for small particles, prevails over the capillary suction that is often assumed to be the dominant effect. We emphasize this point using a simple classroom demonstration, and then derive the physical conditions leading to mutual attraction or repulsion. We also quantify the force of interaction in some particular instances and present a simple dynamical model of this interaction. The results obtained from this model are then validated by comparison to experimental results for the mutual attraction of two identical spherical particles. We conclude by looking at some of the applications of the effect that can be found in the natural and manmade worlds.